Page 1
FINAL JEE –MAIN EXAMINATION – APRIL, 2024
(Held On Saturday 06
th
April, 2024) TIME : 3 : 00 PM to 6 : 00 PM
NOON
MATHEMATICS TEST PAPER WITH SOLUTION
SECTION-A
1. Let ABC be an equilateral triangle. A new triangle
is formed by joining the middle points of all sides
of the triangle ABC and the same process is
repeated infinitely many times. If P is the sum of
perimeters and Q is be the sum of areas of all the
triangles formed in this process, then:
(1)
2
P 36 3Q ?] (2)
2
P 6 3Q ?] (3)
2
P 36 3Q ?] (4)
2
P 72 3Q ?] Ans. (1)
Sol.
a/2
a
a
a
Area of first
2
3a
4
?d?]
Area of second
2 2 2
3a a 3a
4 4 16
?d ?] ?] Area of third
2
a
64
?S ?d?]
sum of area =
2
3a 1 1
1 ....
4 4 16
????
?K?K
????
????
2 2
3a 1 a
Q
3
4
3
4
?]?]
perimeter of 1
st
?d = 3a
perimeter of 2
nd
?d =
3a
2
perimeter of 3
rd
?d =
3a
4
1 1
P 3a 1 ...
2 4
????
?] ?K ?K ?K????
????
P = 3a.2 = 6a
P
a
6
?] 2
1 P
Q
36
3
?]??
2
P 36 3Q ?] 2. Let A = {1, 2, 3, 4, 5}. Let R be a relation on A
defined by xRy if and only if 4x ?? ?@ 5y. Let m be the
number of elements in R and n be the minimum
number of elements from A × A that are required
to be added to R to make it a symmetric relation.
Then m + n is equal to:
(1) 24 (2) 23
(3) 25 (4) 26
Ans. (3)
Sol. Given : 4x ?? 5y
then
?H ?I ?? R 1,1 ,(1,2),(1,3),(1,4),(1,5),(2,2),(2,3),(2,4)
(2,5),(3,3),(3,4),(3,5),(4,4),(4,5),(5,4),(5,5)}
?] i.e. 16 elements.
i.e. m = 16
Now to make R a symmetric relation add
{(2,1)(3,2)(4,3)(3,1)(4,2)(5,3)(4,1)(5,2)(5,1)}
i.e. n = 9
So m + n = 25
3. If three letters can be posted to any one of the 5
different addresses, then the probability that the
three letters are posted to exactly two addresses is:
(1)
12
25
(2)
18
25
(3)
4
25
(4)
6
25
Ans. (1)
Sol. Total method = 5
3
faverable =
?H ?I 5 3
2
C 2 – 2 60 ?] probability =
60 12
125 25
?]
Page 2
FINAL JEE –MAIN EXAMINATION – APRIL, 2024
(Held On Saturday 06
th
April, 2024) TIME : 3 : 00 PM to 6 : 00 PM
NOON
MATHEMATICS TEST PAPER WITH SOLUTION
SECTION-A
1. Let ABC be an equilateral triangle. A new triangle
is formed by joining the middle points of all sides
of the triangle ABC and the same process is
repeated infinitely many times. If P is the sum of
perimeters and Q is be the sum of areas of all the
triangles formed in this process, then:
(1)
2
P 36 3Q ?] (2)
2
P 6 3Q ?] (3)
2
P 36 3Q ?] (4)
2
P 72 3Q ?] Ans. (1)
Sol.
a/2
a
a
a
Area of first
2
3a
4
?d?]
Area of second
2 2 2
3a a 3a
4 4 16
?d ?] ?] Area of third
2
a
64
?S ?d?]
sum of area =
2
3a 1 1
1 ....
4 4 16
????
?K?K
????
????
2 2
3a 1 a
Q
3
4
3
4
?]?]
perimeter of 1
st
?d = 3a
perimeter of 2
nd
?d =
3a
2
perimeter of 3
rd
?d =
3a
4
1 1
P 3a 1 ...
2 4
????
?] ?K ?K ?K????
????
P = 3a.2 = 6a
P
a
6
?] 2
1 P
Q
36
3
?]??
2
P 36 3Q ?] 2. Let A = {1, 2, 3, 4, 5}. Let R be a relation on A
defined by xRy if and only if 4x ?? ?@ 5y. Let m be the
number of elements in R and n be the minimum
number of elements from A × A that are required
to be added to R to make it a symmetric relation.
Then m + n is equal to:
(1) 24 (2) 23
(3) 25 (4) 26
Ans. (3)
Sol. Given : 4x ?? 5y
then
?H ?I ?? R 1,1 ,(1,2),(1,3),(1,4),(1,5),(2,2),(2,3),(2,4)
(2,5),(3,3),(3,4),(3,5),(4,4),(4,5),(5,4),(5,5)}
?] i.e. 16 elements.
i.e. m = 16
Now to make R a symmetric relation add
{(2,1)(3,2)(4,3)(3,1)(4,2)(5,3)(4,1)(5,2)(5,1)}
i.e. n = 9
So m + n = 25
3. If three letters can be posted to any one of the 5
different addresses, then the probability that the
three letters are posted to exactly two addresses is:
(1)
12
25
(2)
18
25
(3)
4
25
(4)
6
25
Ans. (1)
Sol. Total method = 5
3
faverable =
?H ?I 5 3
2
C 2 – 2 60 ?] probability =
60 12
125 25
?] 4. Suppose the solution of the differential equation
dy (2 )x y 2
dx x 2 y ( 4 )
?K ?? ?M ?? ?K ?] ?? ?M ?? ?M ?? ?? ?M ?? represents a circle
passing through origin. Then the radius of this
circle is :
(1) 17 (2)
1
2
(3)
17
2
(4) 2
Ans. (3)
Sol.
?H ?I ?H ?I dy 2 x – y 2
dx x – y 2 4
?K ?? ?? ?K ?] ?? ?? ?K ?? ?K ??
?H ?I xdy – (2 )ydy 4 dy 2 xdx – ydx 2dx ?? ?? ?K ?? ?K ?? ?] ?K ?? ?? ?K
?H ?I (xdy ydx) – (2 )ydy 4 dy 2 xdx 2dx ?? ?K ?? ?K ?? ?K ?? ?] ?K ?? ?K
?H ?I ?H ?I 2 2
2 y 2 x
xy – 4 y
2 2
?? ?K ?? ?K??
?? ?K ?? ?]
0 ?? ?? ?] for this to be circle
?H ?I 2
2
x
2 y 2x – 4 y 0
2
?K ?? ?K ?? ?K ?? ?]
2 + a = 2a
coeff. of
x
2
= y
2
2 ?? ?? ?]
i.e. 2x
2
+ 2y
2
+ 2x – 8y = 0
x
2
+ y
2
+ x – 4y = 0
1 17
rd 4
4 2
?] ?K ?]
5. If the locus of the point, whose distances from the
point (2, 1) and (1, 3) are in the ratio 5 : 4, is
ax
2
+ by
2
+ cxy + dx + ey + 170 = 0, then the value
of a
2
+ 2b + 3c + 4d + e is equal to:
(1) 5 (2) –27
(3) 37 (4) 437
Ans. (3)
Sol. let P(x, y)
?H ?I ?H ?I ?H ?I 2
2
2 2
x – 2 (y – 1) 25
16
x – 1 y – 3
?K ?] ?K
9x
2
+ 9y
2
+ 14x – 118y + 170 = 0
a
2
+ 2b + 3c + 4d + e
= 81 + 18 + 0 + 56 – 118
= 155 – 118
= 37
6.
?H ?I 2 2
2
3 3 3 2 2 2
n
(1 1)(n 1) (2 2)(n 2) ..... · 1
(n 1) (n 1)
lim
(1 2 ..... n ) (1 2 ..... n )
????
?M ?M ?K ?M ?M ?K ?K ?M ?M ?M ?K ?K ?K ?M ?K ?K ?K is equal to:
(1)
2
3
(2)
1
3
(3)
3
4
(4)
1
2
Ans. (2)
Sol.
?H ?I ?H ?I n–1
2
r 1
n n
n
3 2
r 1 r 1
r – r n – r
lim
r – r
?] ????
?]?]
?? ????
?H ?I ?H ?I ?H ?I ?H ?I ?H ?I n–1
3 2
r 1
2
n
–r r n 1 – nr
lim
n n 1 n n 1 2n 1
–
2 6
?] ????
?K?K
???? ?K ?K ?K ????
????
??
?H ?I ?H ?I ?H ?I ?H ?I ?H ?I 2
2
n
n – 1 n n 1 n – 1 n(2n – 1) n (n – 1)
–
2 6 2
lim
n(n 1) n n 1 2n 1
–
2 2 3
????
????
?K ?K ????
????
???? ?K ?K ?K ????
????
?H ?I ?H ?I ?H ?I 2
n
n n – 1 –n n – 1 n 1 (2n – 1)
–n
2 2 3
lim
n(n 1) 3n 3n – 4n – 2
2 6
????
???? ?K ?K????
????
?K?K
?H ?I ?H ?I ?H ?I ?H ?I ?H ?I 2 2
2
n
n – 1 –3n 3n 2 2n n – 1 – 6
lim
n 1 3n – n – 2
????
?K ?K ?K ?K
?H ?I ?H ?I ?H ?I ?H ?I 2
2
n
n –1 n 5n – 8 1
lim
3
n 1 3n – n – 2
????
?K ?] ?K
7. Let 0 ?? r ?? n. If
n+1
C
r+1
:
n
C
r
:
n–1
C
r–1
= 55 : 35 : 21,
then 2n + 5r is equal to:
(1) 60 (2) 62
(3) 50 (4) 55
Ans. (3)
Ans.
n 1
r
n
r
C 55
35 C
?K ?]
?H ?I ?H ?I ?H ?I n 1 ! r! n – r ! 11
!
r 1 !(n – r) n! 7
?K ?] ?K
?H ?I n 1 11
r 1 7
?K ?] ?K
Page 3
FINAL JEE –MAIN EXAMINATION – APRIL, 2024
(Held On Saturday 06
th
April, 2024) TIME : 3 : 00 PM to 6 : 00 PM
NOON
MATHEMATICS TEST PAPER WITH SOLUTION
SECTION-A
1. Let ABC be an equilateral triangle. A new triangle
is formed by joining the middle points of all sides
of the triangle ABC and the same process is
repeated infinitely many times. If P is the sum of
perimeters and Q is be the sum of areas of all the
triangles formed in this process, then:
(1)
2
P 36 3Q ?] (2)
2
P 6 3Q ?] (3)
2
P 36 3Q ?] (4)
2
P 72 3Q ?] Ans. (1)
Sol.
a/2
a
a
a
Area of first
2
3a
4
?d?]
Area of second
2 2 2
3a a 3a
4 4 16
?d ?] ?] Area of third
2
a
64
?S ?d?]
sum of area =
2
3a 1 1
1 ....
4 4 16
????
?K?K
????
????
2 2
3a 1 a
Q
3
4
3
4
?]?]
perimeter of 1
st
?d = 3a
perimeter of 2
nd
?d =
3a
2
perimeter of 3
rd
?d =
3a
4
1 1
P 3a 1 ...
2 4
????
?] ?K ?K ?K????
????
P = 3a.2 = 6a
P
a
6
?] 2
1 P
Q
36
3
?]??
2
P 36 3Q ?] 2. Let A = {1, 2, 3, 4, 5}. Let R be a relation on A
defined by xRy if and only if 4x ?? ?@ 5y. Let m be the
number of elements in R and n be the minimum
number of elements from A × A that are required
to be added to R to make it a symmetric relation.
Then m + n is equal to:
(1) 24 (2) 23
(3) 25 (4) 26
Ans. (3)
Sol. Given : 4x ?? 5y
then
?H ?I ?? R 1,1 ,(1,2),(1,3),(1,4),(1,5),(2,2),(2,3),(2,4)
(2,5),(3,3),(3,4),(3,5),(4,4),(4,5),(5,4),(5,5)}
?] i.e. 16 elements.
i.e. m = 16
Now to make R a symmetric relation add
{(2,1)(3,2)(4,3)(3,1)(4,2)(5,3)(4,1)(5,2)(5,1)}
i.e. n = 9
So m + n = 25
3. If three letters can be posted to any one of the 5
different addresses, then the probability that the
three letters are posted to exactly two addresses is:
(1)
12
25
(2)
18
25
(3)
4
25
(4)
6
25
Ans. (1)
Sol. Total method = 5
3
faverable =
?H ?I 5 3
2
C 2 – 2 60 ?] probability =
60 12
125 25
?] 4. Suppose the solution of the differential equation
dy (2 )x y 2
dx x 2 y ( 4 )
?K ?? ?M ?? ?K ?] ?? ?M ?? ?M ?? ?? ?M ?? represents a circle
passing through origin. Then the radius of this
circle is :
(1) 17 (2)
1
2
(3)
17
2
(4) 2
Ans. (3)
Sol.
?H ?I ?H ?I dy 2 x – y 2
dx x – y 2 4
?K ?? ?? ?K ?] ?? ?? ?K ?? ?K ??
?H ?I xdy – (2 )ydy 4 dy 2 xdx – ydx 2dx ?? ?? ?K ?? ?K ?? ?] ?K ?? ?? ?K
?H ?I (xdy ydx) – (2 )ydy 4 dy 2 xdx 2dx ?? ?K ?? ?K ?? ?K ?? ?] ?K ?? ?K
?H ?I ?H ?I 2 2
2 y 2 x
xy – 4 y
2 2
?? ?K ?? ?K??
?? ?K ?? ?]
0 ?? ?? ?] for this to be circle
?H ?I 2
2
x
2 y 2x – 4 y 0
2
?K ?? ?K ?? ?K ?? ?]
2 + a = 2a
coeff. of
x
2
= y
2
2 ?? ?? ?]
i.e. 2x
2
+ 2y
2
+ 2x – 8y = 0
x
2
+ y
2
+ x – 4y = 0
1 17
rd 4
4 2
?] ?K ?]
5. If the locus of the point, whose distances from the
point (2, 1) and (1, 3) are in the ratio 5 : 4, is
ax
2
+ by
2
+ cxy + dx + ey + 170 = 0, then the value
of a
2
+ 2b + 3c + 4d + e is equal to:
(1) 5 (2) –27
(3) 37 (4) 437
Ans. (3)
Sol. let P(x, y)
?H ?I ?H ?I ?H ?I 2
2
2 2
x – 2 (y – 1) 25
16
x – 1 y – 3
?K ?] ?K
9x
2
+ 9y
2
+ 14x – 118y + 170 = 0
a
2
+ 2b + 3c + 4d + e
= 81 + 18 + 0 + 56 – 118
= 155 – 118
= 37
6.
?H ?I 2 2
2
3 3 3 2 2 2
n
(1 1)(n 1) (2 2)(n 2) ..... · 1
(n 1) (n 1)
lim
(1 2 ..... n ) (1 2 ..... n )
????
?M ?M ?K ?M ?M ?K ?K ?M ?M ?M ?K ?K ?K ?M ?K ?K ?K is equal to:
(1)
2
3
(2)
1
3
(3)
3
4
(4)
1
2
Ans. (2)
Sol.
?H ?I ?H ?I n–1
2
r 1
n n
n
3 2
r 1 r 1
r – r n – r
lim
r – r
?] ????
?]?]
?? ????
?H ?I ?H ?I ?H ?I ?H ?I ?H ?I n–1
3 2
r 1
2
n
–r r n 1 – nr
lim
n n 1 n n 1 2n 1
–
2 6
?] ????
?K?K
???? ?K ?K ?K ????
????
??
?H ?I ?H ?I ?H ?I ?H ?I ?H ?I 2
2
n
n – 1 n n 1 n – 1 n(2n – 1) n (n – 1)
–
2 6 2
lim
n(n 1) n n 1 2n 1
–
2 2 3
????
????
?K ?K ????
????
???? ?K ?K ?K ????
????
?H ?I ?H ?I ?H ?I 2
n
n n – 1 –n n – 1 n 1 (2n – 1)
–n
2 2 3
lim
n(n 1) 3n 3n – 4n – 2
2 6
????
???? ?K ?K????
????
?K?K
?H ?I ?H ?I ?H ?I ?H ?I ?H ?I 2 2
2
n
n – 1 –3n 3n 2 2n n – 1 – 6
lim
n 1 3n – n – 2
????
?K ?K ?K ?K
?H ?I ?H ?I ?H ?I ?H ?I 2
2
n
n –1 n 5n – 8 1
lim
3
n 1 3n – n – 2
????
?K ?] ?K
7. Let 0 ?? r ?? n. If
n+1
C
r+1
:
n
C
r
:
n–1
C
r–1
= 55 : 35 : 21,
then 2n + 5r is equal to:
(1) 60 (2) 62
(3) 50 (4) 55
Ans. (3)
Ans.
n 1
r
n
r
C 55
35 C
?K ?]
?H ?I ?H ?I ?H ?I n 1 ! r! n – r ! 11
!
r 1 !(n – r) n! 7
?K ?] ?K
?H ?I n 1 11
r 1 7
?K ?] ?K
7n = 4 + 11r
n
r
n–1
r–1
C 35
21 C
?]
?H ?I n! (r –1)!(n – r)! 5
r! n – r ! (n –1)! 3
?]?]
n 5
r 3
?]
3n = 5r
By solving r = 6 n = 10
2n + 5r = 50
8. A software company sets up m number of
computer systems to finish an assignment in
17 days. If 4 computer systems crashed on the start
of the second day, 4 more computer systems
crashed on the start of the third day and so on, then
it took 8 more days to finish the assignment. The
value of m is equal to :
(1) 125 (2) 150
(3) 180 (4) 160
Ans. (2)
Sol. 17m = m + (m – 4) + (m – 4 × 2)...+...(m – 4 × 24)
17 m = 25m – 4 (1 + 2 ...24)
4 24 25
8m 150
2
????
?]?]
9. If z
1
, z
2
are two distinct complex number such that
1 2
1 2
z 2z
2
1
z z
2
?M ?] ?M , then
(1) either z
1
lies on a circle of radius 1 or z
2
lies on a
circle of radius
1
2
(2) either z
1
lies on a circle of radius
1
2
or z
2
lies on
a circle of radius 1.
(3) z
1
lies on a circle of radius
1
2
and z
2
lies on a
circle of radius 1.
(4) both z
1
and z
2
lie on the same circle.
Ans. (1)
Sol.
1 2 1 2
1 2 1 2
z – 2z z – 2z
4
1 1
– z z – z z
2 2
???]
2 2
1 1 2 1 2 2
z 2z z – 2z z 4 z ?K
2 2
1 2 1 2
1 2
z z z z 1
4 – – z z
4 2 2
????
?]?K
????
????
1 1 2 2 1 1 2 2
z z 2z 2z – z z 2z 2z – 1 0 ?K ?? ?]
?H ?I ?H ?I 1 2 2
z,z –1 1– 2z 2z 0 ???]
?H ?I ?H ?I 2 2
1 2
z –1 2z –1 0 ?]
10. If the function
2x
1
f(x)
x
????
?] ????
????
; x > 0 attains the
maximum value at
1
x
e
?] then :
(1)
e
e
?? ?\?? (2)
2 e
e (2 )
?? ?\??
(3)
e
e
?? ?^?? (4)
(2e)
(2e)
?? ?^??
Ans. (3)
Sol. Let
2x
1
y
x
????
?] ????
????
?? ny =
1
2x n
x
????
????
????
ny –2x nx ?]
?H ?I 1 dy
–2 1 nx
y dx
?]?K
for
1
x
e
?^ f
n
is decreasing
so, e < ?? ?@ ?@ 2e 2
1 1
e
?? ?? ?? ?? ?? ?^ ?? ?? ?? ?? ?? ?? ?? ?? ??
e
?? >
?? e
11. Let
ˆˆ ˆ
a 6i j k ?] ?K ?M and
ˆˆ
b i j ?]?K . If c is a is vector
such that 6, a.c 6 , 2 2
c c c a
?? ?] ?] ?M and the
angle between a b ?? and c is 60°, then ?H ?I c
a b
?? ??
is equal to:
(1)
?H ?I 9
6 6
2
?M (2)
3
3
2
(3)
3
6
2
(4)
?H ?I 9
6 6
2
?K
Ans. (4)
Page 4
FINAL JEE –MAIN EXAMINATION – APRIL, 2024
(Held On Saturday 06
th
April, 2024) TIME : 3 : 00 PM to 6 : 00 PM
NOON
MATHEMATICS TEST PAPER WITH SOLUTION
SECTION-A
1. Let ABC be an equilateral triangle. A new triangle
is formed by joining the middle points of all sides
of the triangle ABC and the same process is
repeated infinitely many times. If P is the sum of
perimeters and Q is be the sum of areas of all the
triangles formed in this process, then:
(1)
2
P 36 3Q ?] (2)
2
P 6 3Q ?] (3)
2
P 36 3Q ?] (4)
2
P 72 3Q ?] Ans. (1)
Sol.
a/2
a
a
a
Area of first
2
3a
4
?d?]
Area of second
2 2 2
3a a 3a
4 4 16
?d ?] ?] Area of third
2
a
64
?S ?d?]
sum of area =
2
3a 1 1
1 ....
4 4 16
????
?K?K
????
????
2 2
3a 1 a
Q
3
4
3
4
?]?]
perimeter of 1
st
?d = 3a
perimeter of 2
nd
?d =
3a
2
perimeter of 3
rd
?d =
3a
4
1 1
P 3a 1 ...
2 4
????
?] ?K ?K ?K????
????
P = 3a.2 = 6a
P
a
6
?] 2
1 P
Q
36
3
?]??
2
P 36 3Q ?] 2. Let A = {1, 2, 3, 4, 5}. Let R be a relation on A
defined by xRy if and only if 4x ?? ?@ 5y. Let m be the
number of elements in R and n be the minimum
number of elements from A × A that are required
to be added to R to make it a symmetric relation.
Then m + n is equal to:
(1) 24 (2) 23
(3) 25 (4) 26
Ans. (3)
Sol. Given : 4x ?? 5y
then
?H ?I ?? R 1,1 ,(1,2),(1,3),(1,4),(1,5),(2,2),(2,3),(2,4)
(2,5),(3,3),(3,4),(3,5),(4,4),(4,5),(5,4),(5,5)}
?] i.e. 16 elements.
i.e. m = 16
Now to make R a symmetric relation add
{(2,1)(3,2)(4,3)(3,1)(4,2)(5,3)(4,1)(5,2)(5,1)}
i.e. n = 9
So m + n = 25
3. If three letters can be posted to any one of the 5
different addresses, then the probability that the
three letters are posted to exactly two addresses is:
(1)
12
25
(2)
18
25
(3)
4
25
(4)
6
25
Ans. (1)
Sol. Total method = 5
3
faverable =
?H ?I 5 3
2
C 2 – 2 60 ?] probability =
60 12
125 25
?] 4. Suppose the solution of the differential equation
dy (2 )x y 2
dx x 2 y ( 4 )
?K ?? ?M ?? ?K ?] ?? ?M ?? ?M ?? ?? ?M ?? represents a circle
passing through origin. Then the radius of this
circle is :
(1) 17 (2)
1
2
(3)
17
2
(4) 2
Ans. (3)
Sol.
?H ?I ?H ?I dy 2 x – y 2
dx x – y 2 4
?K ?? ?? ?K ?] ?? ?? ?K ?? ?K ??
?H ?I xdy – (2 )ydy 4 dy 2 xdx – ydx 2dx ?? ?? ?K ?? ?K ?? ?] ?K ?? ?? ?K
?H ?I (xdy ydx) – (2 )ydy 4 dy 2 xdx 2dx ?? ?K ?? ?K ?? ?K ?? ?] ?K ?? ?K
?H ?I ?H ?I 2 2
2 y 2 x
xy – 4 y
2 2
?? ?K ?? ?K??
?? ?K ?? ?]
0 ?? ?? ?] for this to be circle
?H ?I 2
2
x
2 y 2x – 4 y 0
2
?K ?? ?K ?? ?K ?? ?]
2 + a = 2a
coeff. of
x
2
= y
2
2 ?? ?? ?]
i.e. 2x
2
+ 2y
2
+ 2x – 8y = 0
x
2
+ y
2
+ x – 4y = 0
1 17
rd 4
4 2
?] ?K ?]
5. If the locus of the point, whose distances from the
point (2, 1) and (1, 3) are in the ratio 5 : 4, is
ax
2
+ by
2
+ cxy + dx + ey + 170 = 0, then the value
of a
2
+ 2b + 3c + 4d + e is equal to:
(1) 5 (2) –27
(3) 37 (4) 437
Ans. (3)
Sol. let P(x, y)
?H ?I ?H ?I ?H ?I 2
2
2 2
x – 2 (y – 1) 25
16
x – 1 y – 3
?K ?] ?K
9x
2
+ 9y
2
+ 14x – 118y + 170 = 0
a
2
+ 2b + 3c + 4d + e
= 81 + 18 + 0 + 56 – 118
= 155 – 118
= 37
6.
?H ?I 2 2
2
3 3 3 2 2 2
n
(1 1)(n 1) (2 2)(n 2) ..... · 1
(n 1) (n 1)
lim
(1 2 ..... n ) (1 2 ..... n )
????
?M ?M ?K ?M ?M ?K ?K ?M ?M ?M ?K ?K ?K ?M ?K ?K ?K is equal to:
(1)
2
3
(2)
1
3
(3)
3
4
(4)
1
2
Ans. (2)
Sol.
?H ?I ?H ?I n–1
2
r 1
n n
n
3 2
r 1 r 1
r – r n – r
lim
r – r
?] ????
?]?]
?? ????
?H ?I ?H ?I ?H ?I ?H ?I ?H ?I n–1
3 2
r 1
2
n
–r r n 1 – nr
lim
n n 1 n n 1 2n 1
–
2 6
?] ????
?K?K
???? ?K ?K ?K ????
????
??
?H ?I ?H ?I ?H ?I ?H ?I ?H ?I 2
2
n
n – 1 n n 1 n – 1 n(2n – 1) n (n – 1)
–
2 6 2
lim
n(n 1) n n 1 2n 1
–
2 2 3
????
????
?K ?K ????
????
???? ?K ?K ?K ????
????
?H ?I ?H ?I ?H ?I 2
n
n n – 1 –n n – 1 n 1 (2n – 1)
–n
2 2 3
lim
n(n 1) 3n 3n – 4n – 2
2 6
????
???? ?K ?K????
????
?K?K
?H ?I ?H ?I ?H ?I ?H ?I ?H ?I 2 2
2
n
n – 1 –3n 3n 2 2n n – 1 – 6
lim
n 1 3n – n – 2
????
?K ?K ?K ?K
?H ?I ?H ?I ?H ?I ?H ?I 2
2
n
n –1 n 5n – 8 1
lim
3
n 1 3n – n – 2
????
?K ?] ?K
7. Let 0 ?? r ?? n. If
n+1
C
r+1
:
n
C
r
:
n–1
C
r–1
= 55 : 35 : 21,
then 2n + 5r is equal to:
(1) 60 (2) 62
(3) 50 (4) 55
Ans. (3)
Ans.
n 1
r
n
r
C 55
35 C
?K ?]
?H ?I ?H ?I ?H ?I n 1 ! r! n – r ! 11
!
r 1 !(n – r) n! 7
?K ?] ?K
?H ?I n 1 11
r 1 7
?K ?] ?K
7n = 4 + 11r
n
r
n–1
r–1
C 35
21 C
?]
?H ?I n! (r –1)!(n – r)! 5
r! n – r ! (n –1)! 3
?]?]
n 5
r 3
?]
3n = 5r
By solving r = 6 n = 10
2n + 5r = 50
8. A software company sets up m number of
computer systems to finish an assignment in
17 days. If 4 computer systems crashed on the start
of the second day, 4 more computer systems
crashed on the start of the third day and so on, then
it took 8 more days to finish the assignment. The
value of m is equal to :
(1) 125 (2) 150
(3) 180 (4) 160
Ans. (2)
Sol. 17m = m + (m – 4) + (m – 4 × 2)...+...(m – 4 × 24)
17 m = 25m – 4 (1 + 2 ...24)
4 24 25
8m 150
2
????
?]?]
9. If z
1
, z
2
are two distinct complex number such that
1 2
1 2
z 2z
2
1
z z
2
?M ?] ?M , then
(1) either z
1
lies on a circle of radius 1 or z
2
lies on a
circle of radius
1
2
(2) either z
1
lies on a circle of radius
1
2
or z
2
lies on
a circle of radius 1.
(3) z
1
lies on a circle of radius
1
2
and z
2
lies on a
circle of radius 1.
(4) both z
1
and z
2
lie on the same circle.
Ans. (1)
Sol.
1 2 1 2
1 2 1 2
z – 2z z – 2z
4
1 1
– z z – z z
2 2
???]
2 2
1 1 2 1 2 2
z 2z z – 2z z 4 z ?K
2 2
1 2 1 2
1 2
z z z z 1
4 – – z z
4 2 2
????
?]?K
????
????
1 1 2 2 1 1 2 2
z z 2z 2z – z z 2z 2z – 1 0 ?K ?? ?]
?H ?I ?H ?I 1 2 2
z,z –1 1– 2z 2z 0 ???]
?H ?I ?H ?I 2 2
1 2
z –1 2z –1 0 ?]
10. If the function
2x
1
f(x)
x
????
?] ????
????
; x > 0 attains the
maximum value at
1
x
e
?] then :
(1)
e
e
?? ?\?? (2)
2 e
e (2 )
?? ?\??
(3)
e
e
?? ?^?? (4)
(2e)
(2e)
?? ?^??
Ans. (3)
Sol. Let
2x
1
y
x
????
?] ????
????
?? ny =
1
2x n
x
????
????
????
ny –2x nx ?]
?H ?I 1 dy
–2 1 nx
y dx
?]?K
for
1
x
e
?^ f
n
is decreasing
so, e < ?? ?@ ?@ 2e 2
1 1
e
?? ?? ?? ?? ?? ?^ ?? ?? ?? ?? ?? ?? ?? ?? ??
e
?? >
?? e
11. Let
ˆˆ ˆ
a 6i j k ?] ?K ?M and
ˆˆ
b i j ?]?K . If c is a is vector
such that 6, a.c 6 , 2 2
c c c a
?? ?] ?] ?M and the
angle between a b ?? and c is 60°, then ?H ?I c
a b
?? ??
is equal to:
(1)
?H ?I 9
6 6
2
?M (2)
3
3
2
(3)
3
6
2
(4)
?H ?I 9
6 6
2
?K
Ans. (4)
Sol.
?H ?I 3
a b c a b c
2
?? ?? ?] ??
c – a 2 2 ?]
2 2
c a – 2c a 8 ?K ?? ?]
2
z 38 –12 z 8 ?K?]
2
z –12 z 30 0 ?K?]
12 144 –120
z
2
?? ?]
12 2 6
2
?? ?]
z 6 6 ?]?K
ˆˆ ˆ
j k
a b 6 1 –1
1 1 0
???]
ˆˆ ˆ
– j 5k ?K
a b 27 ???]
?H ?I ?H ?I 3
a b z 27 6 6
2
?? ?? ?] ?K
?H ?I 9
6 6
2
?K
12. If all the words with or without meaning made
using all the letters of the word "NAGPUR" are
arranged as in a dictionary, then the word at 315
th
position in this arrangement is :
(1) NRAGUP (2) NRAGPU
(3) NRAPGU (4) NRAPUG
Ans. (3)
Sol. NAGPUR
A ?? 5! = 120
G ® 5! = 120 240
NA ® 4! = 24 264
NG ® 4! = 24 288
NP ® 4! = 24 312
NRAGPU = 1 313
NRAGUP 314
NRAPGU 315
13. Suppose for a differentiable function h, h(0) = 0,
h(1) = 1 and h'(0) = h'(1) = 2. If g(x) = h(e
x
) e
h(x)
,
then g'(0) is equal to:
(1) 5 (2) 3
(3) 8 (4) 4
Ans. (4)
Sol.
?H ?I ?H ?I x h(x)
g x h e e ?]??
?H ?I ?H ?I x h(x) h(x) x x
g' x h(e ) e h'(x) e h' e e ?] ?? ?? ?K ??
h(0) h(0)
g'(0) h(1)e h'(0) e h'(1) ?]?K
= 2 + 2 = 4
14. Let P ( ?? ?L?@ ?? ?L?@ ?? ) be the image of the point Q(3, –3, 1)
in the line
x 0 y 3 z 1
1 1 1
?M ?M ?M ?]?]
?M and R be the point
(2, 5, –1). If the area of the triangle PQR is ?? and
?? 2
= 14K, then K is equal to:
(1) 36 (2) 72
(3) 18 (4) 81
Ans. (4)
Sol.
?? ?@ R(2,5,–1)
S
P( ?? , ?? , ?? )
Q(3,–3,1)
RQ 1 64 4 69 ?] ?K ?K ?]
ˆˆ ˆ
RQ – 8j 2k ?]?K
ˆˆ ˆ
RS j – k ?]?K
RQ RS 1 – 8 – 2 9
cos
69 3 3 23 RQ RS
?? ?? ?] ?] ?]
3 RS RS
cos
RQ
23 69
?? ?] ?] ?]
RS 3 3 ?]
14 QS
sin
23 69
?? ?] ?]
QS 42 ?]
area =
1
2QS RS 42 3 3
2
?? ?? ?] ??
9 14 ???]
2
81.14 14k ?? ?] ?]
k = 81
Page 5
FINAL JEE –MAIN EXAMINATION – APRIL, 2024
(Held On Saturday 06
th
April, 2024) TIME : 3 : 00 PM to 6 : 00 PM
NOON
MATHEMATICS TEST PAPER WITH SOLUTION
SECTION-A
1. Let ABC be an equilateral triangle. A new triangle
is formed by joining the middle points of all sides
of the triangle ABC and the same process is
repeated infinitely many times. If P is the sum of
perimeters and Q is be the sum of areas of all the
triangles formed in this process, then:
(1)
2
P 36 3Q ?] (2)
2
P 6 3Q ?] (3)
2
P 36 3Q ?] (4)
2
P 72 3Q ?] Ans. (1)
Sol.
a/2
a
a
a
Area of first
2
3a
4
?d?]
Area of second
2 2 2
3a a 3a
4 4 16
?d ?] ?] Area of third
2
a
64
?S ?d?]
sum of area =
2
3a 1 1
1 ....
4 4 16
????
?K?K
????
????
2 2
3a 1 a
Q
3
4
3
4
?]?]
perimeter of 1
st
?d = 3a
perimeter of 2
nd
?d =
3a
2
perimeter of 3
rd
?d =
3a
4
1 1
P 3a 1 ...
2 4
????
?] ?K ?K ?K????
????
P = 3a.2 = 6a
P
a
6
?] 2
1 P
Q
36
3
?]??
2
P 36 3Q ?] 2. Let A = {1, 2, 3, 4, 5}. Let R be a relation on A
defined by xRy if and only if 4x ?? ?@ 5y. Let m be the
number of elements in R and n be the minimum
number of elements from A × A that are required
to be added to R to make it a symmetric relation.
Then m + n is equal to:
(1) 24 (2) 23
(3) 25 (4) 26
Ans. (3)
Sol. Given : 4x ?? 5y
then
?H ?I ?? R 1,1 ,(1,2),(1,3),(1,4),(1,5),(2,2),(2,3),(2,4)
(2,5),(3,3),(3,4),(3,5),(4,4),(4,5),(5,4),(5,5)}
?] i.e. 16 elements.
i.e. m = 16
Now to make R a symmetric relation add
{(2,1)(3,2)(4,3)(3,1)(4,2)(5,3)(4,1)(5,2)(5,1)}
i.e. n = 9
So m + n = 25
3. If three letters can be posted to any one of the 5
different addresses, then the probability that the
three letters are posted to exactly two addresses is:
(1)
12
25
(2)
18
25
(3)
4
25
(4)
6
25
Ans. (1)
Sol. Total method = 5
3
faverable =
?H ?I 5 3
2
C 2 – 2 60 ?] probability =
60 12
125 25
?] 4. Suppose the solution of the differential equation
dy (2 )x y 2
dx x 2 y ( 4 )
?K ?? ?M ?? ?K ?] ?? ?M ?? ?M ?? ?? ?M ?? represents a circle
passing through origin. Then the radius of this
circle is :
(1) 17 (2)
1
2
(3)
17
2
(4) 2
Ans. (3)
Sol.
?H ?I ?H ?I dy 2 x – y 2
dx x – y 2 4
?K ?? ?? ?K ?] ?? ?? ?K ?? ?K ??
?H ?I xdy – (2 )ydy 4 dy 2 xdx – ydx 2dx ?? ?? ?K ?? ?K ?? ?] ?K ?? ?? ?K
?H ?I (xdy ydx) – (2 )ydy 4 dy 2 xdx 2dx ?? ?K ?? ?K ?? ?K ?? ?] ?K ?? ?K
?H ?I ?H ?I 2 2
2 y 2 x
xy – 4 y
2 2
?? ?K ?? ?K??
?? ?K ?? ?]
0 ?? ?? ?] for this to be circle
?H ?I 2
2
x
2 y 2x – 4 y 0
2
?K ?? ?K ?? ?K ?? ?]
2 + a = 2a
coeff. of
x
2
= y
2
2 ?? ?? ?]
i.e. 2x
2
+ 2y
2
+ 2x – 8y = 0
x
2
+ y
2
+ x – 4y = 0
1 17
rd 4
4 2
?] ?K ?]
5. If the locus of the point, whose distances from the
point (2, 1) and (1, 3) are in the ratio 5 : 4, is
ax
2
+ by
2
+ cxy + dx + ey + 170 = 0, then the value
of a
2
+ 2b + 3c + 4d + e is equal to:
(1) 5 (2) –27
(3) 37 (4) 437
Ans. (3)
Sol. let P(x, y)
?H ?I ?H ?I ?H ?I 2
2
2 2
x – 2 (y – 1) 25
16
x – 1 y – 3
?K ?] ?K
9x
2
+ 9y
2
+ 14x – 118y + 170 = 0
a
2
+ 2b + 3c + 4d + e
= 81 + 18 + 0 + 56 – 118
= 155 – 118
= 37
6.
?H ?I 2 2
2
3 3 3 2 2 2
n
(1 1)(n 1) (2 2)(n 2) ..... · 1
(n 1) (n 1)
lim
(1 2 ..... n ) (1 2 ..... n )
????
?M ?M ?K ?M ?M ?K ?K ?M ?M ?M ?K ?K ?K ?M ?K ?K ?K is equal to:
(1)
2
3
(2)
1
3
(3)
3
4
(4)
1
2
Ans. (2)
Sol.
?H ?I ?H ?I n–1
2
r 1
n n
n
3 2
r 1 r 1
r – r n – r
lim
r – r
?] ????
?]?]
?? ????
?H ?I ?H ?I ?H ?I ?H ?I ?H ?I n–1
3 2
r 1
2
n
–r r n 1 – nr
lim
n n 1 n n 1 2n 1
–
2 6
?] ????
?K?K
???? ?K ?K ?K ????
????
??
?H ?I ?H ?I ?H ?I ?H ?I ?H ?I 2
2
n
n – 1 n n 1 n – 1 n(2n – 1) n (n – 1)
–
2 6 2
lim
n(n 1) n n 1 2n 1
–
2 2 3
????
????
?K ?K ????
????
???? ?K ?K ?K ????
????
?H ?I ?H ?I ?H ?I 2
n
n n – 1 –n n – 1 n 1 (2n – 1)
–n
2 2 3
lim
n(n 1) 3n 3n – 4n – 2
2 6
????
???? ?K ?K????
????
?K?K
?H ?I ?H ?I ?H ?I ?H ?I ?H ?I 2 2
2
n
n – 1 –3n 3n 2 2n n – 1 – 6
lim
n 1 3n – n – 2
????
?K ?K ?K ?K
?H ?I ?H ?I ?H ?I ?H ?I 2
2
n
n –1 n 5n – 8 1
lim
3
n 1 3n – n – 2
????
?K ?] ?K
7. Let 0 ?? r ?? n. If
n+1
C
r+1
:
n
C
r
:
n–1
C
r–1
= 55 : 35 : 21,
then 2n + 5r is equal to:
(1) 60 (2) 62
(3) 50 (4) 55
Ans. (3)
Ans.
n 1
r
n
r
C 55
35 C
?K ?]
?H ?I ?H ?I ?H ?I n 1 ! r! n – r ! 11
!
r 1 !(n – r) n! 7
?K ?] ?K
?H ?I n 1 11
r 1 7
?K ?] ?K
7n = 4 + 11r
n
r
n–1
r–1
C 35
21 C
?]
?H ?I n! (r –1)!(n – r)! 5
r! n – r ! (n –1)! 3
?]?]
n 5
r 3
?]
3n = 5r
By solving r = 6 n = 10
2n + 5r = 50
8. A software company sets up m number of
computer systems to finish an assignment in
17 days. If 4 computer systems crashed on the start
of the second day, 4 more computer systems
crashed on the start of the third day and so on, then
it took 8 more days to finish the assignment. The
value of m is equal to :
(1) 125 (2) 150
(3) 180 (4) 160
Ans. (2)
Sol. 17m = m + (m – 4) + (m – 4 × 2)...+...(m – 4 × 24)
17 m = 25m – 4 (1 + 2 ...24)
4 24 25
8m 150
2
????
?]?]
9. If z
1
, z
2
are two distinct complex number such that
1 2
1 2
z 2z
2
1
z z
2
?M ?] ?M , then
(1) either z
1
lies on a circle of radius 1 or z
2
lies on a
circle of radius
1
2
(2) either z
1
lies on a circle of radius
1
2
or z
2
lies on
a circle of radius 1.
(3) z
1
lies on a circle of radius
1
2
and z
2
lies on a
circle of radius 1.
(4) both z
1
and z
2
lie on the same circle.
Ans. (1)
Sol.
1 2 1 2
1 2 1 2
z – 2z z – 2z
4
1 1
– z z – z z
2 2
???]
2 2
1 1 2 1 2 2
z 2z z – 2z z 4 z ?K
2 2
1 2 1 2
1 2
z z z z 1
4 – – z z
4 2 2
????
?]?K
????
????
1 1 2 2 1 1 2 2
z z 2z 2z – z z 2z 2z – 1 0 ?K ?? ?]
?H ?I ?H ?I 1 2 2
z,z –1 1– 2z 2z 0 ???]
?H ?I ?H ?I 2 2
1 2
z –1 2z –1 0 ?]
10. If the function
2x
1
f(x)
x
????
?] ????
????
; x > 0 attains the
maximum value at
1
x
e
?] then :
(1)
e
e
?? ?\?? (2)
2 e
e (2 )
?? ?\??
(3)
e
e
?? ?^?? (4)
(2e)
(2e)
?? ?^??
Ans. (3)
Sol. Let
2x
1
y
x
????
?] ????
????
?? ny =
1
2x n
x
????
????
????
ny –2x nx ?]
?H ?I 1 dy
–2 1 nx
y dx
?]?K
for
1
x
e
?^ f
n
is decreasing
so, e < ?? ?@ ?@ 2e 2
1 1
e
?? ?? ?? ?? ?? ?^ ?? ?? ?? ?? ?? ?? ?? ?? ??
e
?? >
?? e
11. Let
ˆˆ ˆ
a 6i j k ?] ?K ?M and
ˆˆ
b i j ?]?K . If c is a is vector
such that 6, a.c 6 , 2 2
c c c a
?? ?] ?] ?M and the
angle between a b ?? and c is 60°, then ?H ?I c
a b
?? ??
is equal to:
(1)
?H ?I 9
6 6
2
?M (2)
3
3
2
(3)
3
6
2
(4)
?H ?I 9
6 6
2
?K
Ans. (4)
Sol.
?H ?I 3
a b c a b c
2
?? ?? ?] ??
c – a 2 2 ?]
2 2
c a – 2c a 8 ?K ?? ?]
2
z 38 –12 z 8 ?K?]
2
z –12 z 30 0 ?K?]
12 144 –120
z
2
?? ?]
12 2 6
2
?? ?]
z 6 6 ?]?K
ˆˆ ˆ
j k
a b 6 1 –1
1 1 0
???]
ˆˆ ˆ
– j 5k ?K
a b 27 ???]
?H ?I ?H ?I 3
a b z 27 6 6
2
?? ?? ?] ?K
?H ?I 9
6 6
2
?K
12. If all the words with or without meaning made
using all the letters of the word "NAGPUR" are
arranged as in a dictionary, then the word at 315
th
position in this arrangement is :
(1) NRAGUP (2) NRAGPU
(3) NRAPGU (4) NRAPUG
Ans. (3)
Sol. NAGPUR
A ?? 5! = 120
G ® 5! = 120 240
NA ® 4! = 24 264
NG ® 4! = 24 288
NP ® 4! = 24 312
NRAGPU = 1 313
NRAGUP 314
NRAPGU 315
13. Suppose for a differentiable function h, h(0) = 0,
h(1) = 1 and h'(0) = h'(1) = 2. If g(x) = h(e
x
) e
h(x)
,
then g'(0) is equal to:
(1) 5 (2) 3
(3) 8 (4) 4
Ans. (4)
Sol.
?H ?I ?H ?I x h(x)
g x h e e ?]??
?H ?I ?H ?I x h(x) h(x) x x
g' x h(e ) e h'(x) e h' e e ?] ?? ?? ?K ??
h(0) h(0)
g'(0) h(1)e h'(0) e h'(1) ?]?K
= 2 + 2 = 4
14. Let P ( ?? ?L?@ ?? ?L?@ ?? ) be the image of the point Q(3, –3, 1)
in the line
x 0 y 3 z 1
1 1 1
?M ?M ?M ?]?]
?M and R be the point
(2, 5, –1). If the area of the triangle PQR is ?? and
?? 2
= 14K, then K is equal to:
(1) 36 (2) 72
(3) 18 (4) 81
Ans. (4)
Sol.
?? ?@ R(2,5,–1)
S
P( ?? , ?? , ?? )
Q(3,–3,1)
RQ 1 64 4 69 ?] ?K ?K ?]
ˆˆ ˆ
RQ – 8j 2k ?]?K
ˆˆ ˆ
RS j – k ?]?K
RQ RS 1 – 8 – 2 9
cos
69 3 3 23 RQ RS
?? ?? ?] ?] ?]
3 RS RS
cos
RQ
23 69
?? ?] ?] ?]
RS 3 3 ?]
14 QS
sin
23 69
?? ?] ?]
QS 42 ?]
area =
1
2QS RS 42 3 3
2
?? ?? ?] ??
9 14 ???]
2
81.14 14k ?? ?] ?]
k = 81
15. If P(6, 1) be the orthocentre of the triangle whose
vertices are A(5, –2), B(8, 3) and C(h, k), then the
point C lies on the circle.
(1) x
2
+ y
2
– 65 = 0 (2) x
2
+ y
2
– 74 = 0
(3) x
2
+ y
2
– 61 = 0 (4) x
2
+ y
2
– 52 = 0
Ans. (1)
Sol.
B(8,3)
D C(h, k)
(6,1)P
F E
A(5,–2)
Slope of AD = 3
Slope of BC
1
–
3
?]
equation of BC = 3y + x – 17 = 0
slope of BE = 1
Slope of AC = –1
equation of AC is x + y – 3 = 0
point C is (–4, 7)
16. Let
1
f(x)
7 sin 5x
?] ?M be a function defined on R.
Then the range of the function f(x) is equal to:
(1)
1 1
,
8 5
????
????
????
(2)
1 1
,
7 6
????
????
????
(3)
1 1
,
7 5
????
????
????
(4)
1 1
,
8 6
????
????
????
Ans. (4)
Sol. sin5x ?? [–1,1]
–sin5x ?? [–1, 1]
7 – sin5x ?? [6, 8]
1 1 1
,
7 – sin 5x 8 6
????
?? ????
????
17. Let
ˆˆ ˆ
a 2i j k ?] ?K ?M ,
?H ?I ?H ?I ?H ?Iˆˆ
ˆˆ
b a i i
i j
?] ?? ?? ?? ?K .
Then the square of the projection of a on b is :
(1)
1
5
(2) 2
(3)
1
3
(4)
2
3
Ans. (2)
Sol. ?H ?I ˆˆ ˆ
i j k
ˆˆ
a i j 2 1 –1
1 1 0
?? ?K ?]
ˆˆ ˆ
i – j k ?]?K
?H ?I ?H ?I ˆ ˆ ˆ ˆ ˆ
a i j i k j ?? ?? ?? ?] ?K
?H ?I ?H ?I ?H ?I ˆ ˆ ˆ ˆ ˆ
a i j i i j – k ?? ?? ?? ?? ?]
projection of a on
ˆ
b
a b
b
?? ?]
1 1
2
2
?K ?]?]
18. If the area of the region
2
a 1
(x,y) : y ,1 x 2, 0 a 1
x x
????
?? ?? ?? ?? ?\ ?\ ????
????
is
(log
e
2) –
1
7
then the value of 7a – 3 is equal to:
(1) 2 (2) 0
(3) –1 (4) 1
Ans. (3)
Sol.
a 1 2
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