Page 1
FINAL JEE –MAIN EXAMINATION – APRIL, 2024
(Held On Friday 05
th
April, 2024) TIME : 3 : 00 PM to 6 : 00 PM
MATHEMATICS TEST PAPER WITH SOLUTION
SECTION-A
1. Let ƒ: [–1, 2] ?? R be given by
ƒ(x) = 2x
2
+ x + [x
2
] – [x], where [t] denotes the
greatest integer less than or equal to t. The number
of points, where ƒ is not continuous, is :
(1) 6 (2) 3
(3) 4 (4) 5
Ans. (3)
Sol. Doubtful points : –1, 0, 1, 2 , 3 , 2
at x = 2 , 3
?H ?I 2 2
Cont. Cont.
f(x) 2x x [x] x Discount
?? ?? ????
?] ?K ?M ?K ?]????
at x = –1 :
RHL f(x) (2 1 ( 1)) 0 2
Dis.
f( 1) 2 1 ( 1) 1 3
?? ?] ?M ?M ?M ?K ?] ?? ?? ?M ?] ?M ?M ?M ?K ?] ?? at x = 2 :
LHL f(x) 8 2 1 3 12
Cont.
f(2) 8 2 2 4 12
?? ?] ?K ?M ?K ?] ?? ?? ?] ?K ?M ?K ?] ?? at x = 0 :
LHL 0 0 ( 1) 0 1
Dis.
f(0) 0
?? ?K ?M ?M ?K ?] ?? ?? ?] ?? at x = 1
LHL 2 1 0 0 3
f(1) 3 1 1 3 Cont.
RHL 2 1 1 1 3
?? ?K ?M ?K ?] ?? ?? ?] ?M ?K ?] ?? ?? ?? ?K ?M ?K ?] ?? 2. The differential equation of the family of circles
passing the origin and having center at the line
y = x is :
(1) (x
2
– y
2
+ 2xy)dx = (x
2
– y
2
+ 2xy)dy
(2) (x
2
+ y
2
+ 2xy)dx = (x
2
+ y
2
– 2xy)dy
(3) (x
2
– y
2
+ 2xy)dx = (x
2
– y
2
– 2xy)dy
(4) (x
2
+ y
2
– 2xy)dx = (x
2
+ y
2
+ 2xy)dy
Ans. (3)
Sol. C ?? x
2
+ y
2
+ gx + gy = 0 .....(1)
2x + 2yy' + g + gy' = 0
2x 2yy'
g
1 y'
???? ?K ?]?M
????
?K????
Put in (1)
2 2
2x 2yy'
x y (x y) 0
1 y'
???? ?K ?K ?M ?K ?] ????
?K????
(x
2
– y
2
– 2xy)y' = x
2
– y
2
+ 2xy
3. Let S
1
= {z ?? C : |z| ?? 5},
2
z 1 3 i
S z C : Im 0
1 3 i
???? ????
?K?M ????
?] ?? ?? ???? ????
????
?M ???? ???? ????
and
S
3
= {z ?? C : Re (z) ?? ?@?P }. Then
(1)
125
6
?? (2)
125
24
?? (3)
125
4
?? (4)
125
12
?? Ans. (4)
Sol. S
1
: x
2
+ y
2
?? 25 .....(1)
S
2
: lm of
?H ?I ?H ?I z 1 3 i
0
1 3 i
?K?M
?? ?M lm of
x iy
1 0
1 3 i
????
?K ?K??
????
????
?M????
lm of
?H ?I ?H ?I x iy 1 3 i
0
4
????
?K?K
????
?? ????
????
?? 3 x y 0 ?K?? ......(2)
S
3
: x ?? 0 ......(3)
Area =
?H ?I 2
5
(5)
12
??
Page 2
FINAL JEE –MAIN EXAMINATION – APRIL, 2024
(Held On Friday 05
th
April, 2024) TIME : 3 : 00 PM to 6 : 00 PM
MATHEMATICS TEST PAPER WITH SOLUTION
SECTION-A
1. Let ƒ: [–1, 2] ?? R be given by
ƒ(x) = 2x
2
+ x + [x
2
] – [x], where [t] denotes the
greatest integer less than or equal to t. The number
of points, where ƒ is not continuous, is :
(1) 6 (2) 3
(3) 4 (4) 5
Ans. (3)
Sol. Doubtful points : –1, 0, 1, 2 , 3 , 2
at x = 2 , 3
?H ?I 2 2
Cont. Cont.
f(x) 2x x [x] x Discount
?? ?? ????
?] ?K ?M ?K ?]????
at x = –1 :
RHL f(x) (2 1 ( 1)) 0 2
Dis.
f( 1) 2 1 ( 1) 1 3
?? ?] ?M ?M ?M ?K ?] ?? ?? ?M ?] ?M ?M ?M ?K ?] ?? at x = 2 :
LHL f(x) 8 2 1 3 12
Cont.
f(2) 8 2 2 4 12
?? ?] ?K ?M ?K ?] ?? ?? ?] ?K ?M ?K ?] ?? at x = 0 :
LHL 0 0 ( 1) 0 1
Dis.
f(0) 0
?? ?K ?M ?M ?K ?] ?? ?? ?] ?? at x = 1
LHL 2 1 0 0 3
f(1) 3 1 1 3 Cont.
RHL 2 1 1 1 3
?? ?K ?M ?K ?] ?? ?? ?] ?M ?K ?] ?? ?? ?? ?K ?M ?K ?] ?? 2. The differential equation of the family of circles
passing the origin and having center at the line
y = x is :
(1) (x
2
– y
2
+ 2xy)dx = (x
2
– y
2
+ 2xy)dy
(2) (x
2
+ y
2
+ 2xy)dx = (x
2
+ y
2
– 2xy)dy
(3) (x
2
– y
2
+ 2xy)dx = (x
2
– y
2
– 2xy)dy
(4) (x
2
+ y
2
– 2xy)dx = (x
2
+ y
2
+ 2xy)dy
Ans. (3)
Sol. C ?? x
2
+ y
2
+ gx + gy = 0 .....(1)
2x + 2yy' + g + gy' = 0
2x 2yy'
g
1 y'
???? ?K ?]?M
????
?K????
Put in (1)
2 2
2x 2yy'
x y (x y) 0
1 y'
???? ?K ?K ?M ?K ?] ????
?K????
(x
2
– y
2
– 2xy)y' = x
2
– y
2
+ 2xy
3. Let S
1
= {z ?? C : |z| ?? 5},
2
z 1 3 i
S z C : Im 0
1 3 i
???? ????
?K?M ????
?] ?? ?? ???? ????
????
?M ???? ???? ????
and
S
3
= {z ?? C : Re (z) ?? ?@?P }. Then
(1)
125
6
?? (2)
125
24
?? (3)
125
4
?? (4)
125
12
?? Ans. (4)
Sol. S
1
: x
2
+ y
2
?? 25 .....(1)
S
2
: lm of
?H ?I ?H ?I z 1 3 i
0
1 3 i
?K?M
?? ?M lm of
x iy
1 0
1 3 i
????
?K ?K??
????
????
?M????
lm of
?H ?I ?H ?I x iy 1 3 i
0
4
????
?K?K
????
?? ????
????
?? 3 x y 0 ?K?? ......(2)
S
3
: x ?? 0 ......(3)
Area =
?H ?I 2
5
(5)
12
??
60°
4. The area enclosed between the curves y = x|x| and
y = x – |x| is :
(1)
8
3
(2)
2
3
(3) 1 (4)
4
3
Ans. (4)
Sol.
y = 2x
y = x
2
y = 0
(0,0)
(–2,–4)
y = –x
2
0
2
2
A x 2x
?M ?] ?M ?M ??
4
3
?]
5. 60 words can be made using all the letters of the
word BHBJO, with or without meaning. If these
words are written as in a dictionary, then the 50
th
word is :
(1) OBBHJ (2) HBBJO
(3) OBBJH (4) JBBOH
Ans. (3)
Sol. B B H J O
B _____4! 24 ?]
4!
H _____ 12
2!
?]
4!
J _____ 12
2!
?]
O B B H J
O B B J H ?? 50
th
rank
6. Let
ˆˆ ˆ
a 2i 5j k ?] ?K ?M ,
ˆˆ ˆ
b 2i 2j 2k ?] ?M ?K
and c be three vectors such that
?H ?I ?H ?I ?H ?I ˆ ˆ ˆ
c i a b i a c i ?K ?? ?K ?K ?] ?? ?K
. a.c 29 ?]?M ,
then
?H ?I ˆˆ ˆ
c. 2i j k ?M ?K ?K is equal to :
(1) 10 (2) 5
(3) 15 (4) 12
Ans. (2)
Sol. Let's assume
ˆ
v a b i ?] ?K ?K
ˆˆ ˆ
5i 3j k ?] ?K ?K
and
ˆ
c i p ?K?]
So,
p v a p ?? ?] ??
p v p a 0 ?? ?K ?? ?]
?H ?I p v a 0 ?? ?K ?]
??
?H ?I p v a ?] ?? ?K
?H ?I ˆˆ
c i 7i 8j ?K ?] ?? ?K
?H ?I ˆ ˆ ˆ
a.c a.i a. 7i 8j ?K ?] ?? ?K
?H ?I 29 2 14 40 ?M ?K ?] ?? ?K
1
2
?? ?] ?M
?H ?I ?H ?I ?H ?I ?H ?I ˆ ˆ ˆ ˆ ˆ ˆ ˆ ˆ ˆ ˆ ˆ ˆ
c. 2i j k i. 2i j k 7i 8j . 2i j k ?M ?K ?K ?K ?M ?K ?K ?] ?? ?K ?M ?K ?K ?H ?I 1
14 8 2 5
2
?] ?M ?M ?K ?K ?]
7. Consider three vectors a,b,c . Let a 2, b 3 ?]?]
and a b c ?]?? . If 0,
3
?? ????
????
????
????
is the angle between
the vectors b and c , then the minimum value of
2
27 c a ?M is equal to :
(1) 110 (2) 105
(3) 124 (4) 121
Ans. (3)
Page 3
FINAL JEE –MAIN EXAMINATION – APRIL, 2024
(Held On Friday 05
th
April, 2024) TIME : 3 : 00 PM to 6 : 00 PM
MATHEMATICS TEST PAPER WITH SOLUTION
SECTION-A
1. Let ƒ: [–1, 2] ?? R be given by
ƒ(x) = 2x
2
+ x + [x
2
] – [x], where [t] denotes the
greatest integer less than or equal to t. The number
of points, where ƒ is not continuous, is :
(1) 6 (2) 3
(3) 4 (4) 5
Ans. (3)
Sol. Doubtful points : –1, 0, 1, 2 , 3 , 2
at x = 2 , 3
?H ?I 2 2
Cont. Cont.
f(x) 2x x [x] x Discount
?? ?? ????
?] ?K ?M ?K ?]????
at x = –1 :
RHL f(x) (2 1 ( 1)) 0 2
Dis.
f( 1) 2 1 ( 1) 1 3
?? ?] ?M ?M ?M ?K ?] ?? ?? ?M ?] ?M ?M ?M ?K ?] ?? at x = 2 :
LHL f(x) 8 2 1 3 12
Cont.
f(2) 8 2 2 4 12
?? ?] ?K ?M ?K ?] ?? ?? ?] ?K ?M ?K ?] ?? at x = 0 :
LHL 0 0 ( 1) 0 1
Dis.
f(0) 0
?? ?K ?M ?M ?K ?] ?? ?? ?] ?? at x = 1
LHL 2 1 0 0 3
f(1) 3 1 1 3 Cont.
RHL 2 1 1 1 3
?? ?K ?M ?K ?] ?? ?? ?] ?M ?K ?] ?? ?? ?? ?K ?M ?K ?] ?? 2. The differential equation of the family of circles
passing the origin and having center at the line
y = x is :
(1) (x
2
– y
2
+ 2xy)dx = (x
2
– y
2
+ 2xy)dy
(2) (x
2
+ y
2
+ 2xy)dx = (x
2
+ y
2
– 2xy)dy
(3) (x
2
– y
2
+ 2xy)dx = (x
2
– y
2
– 2xy)dy
(4) (x
2
+ y
2
– 2xy)dx = (x
2
+ y
2
+ 2xy)dy
Ans. (3)
Sol. C ?? x
2
+ y
2
+ gx + gy = 0 .....(1)
2x + 2yy' + g + gy' = 0
2x 2yy'
g
1 y'
???? ?K ?]?M
????
?K????
Put in (1)
2 2
2x 2yy'
x y (x y) 0
1 y'
???? ?K ?K ?M ?K ?] ????
?K????
(x
2
– y
2
– 2xy)y' = x
2
– y
2
+ 2xy
3. Let S
1
= {z ?? C : |z| ?? 5},
2
z 1 3 i
S z C : Im 0
1 3 i
???? ????
?K?M ????
?] ?? ?? ???? ????
????
?M ???? ???? ????
and
S
3
= {z ?? C : Re (z) ?? ?@?P }. Then
(1)
125
6
?? (2)
125
24
?? (3)
125
4
?? (4)
125
12
?? Ans. (4)
Sol. S
1
: x
2
+ y
2
?? 25 .....(1)
S
2
: lm of
?H ?I ?H ?I z 1 3 i
0
1 3 i
?K?M
?? ?M lm of
x iy
1 0
1 3 i
????
?K ?K??
????
????
?M????
lm of
?H ?I ?H ?I x iy 1 3 i
0
4
????
?K?K
????
?? ????
????
?? 3 x y 0 ?K?? ......(2)
S
3
: x ?? 0 ......(3)
Area =
?H ?I 2
5
(5)
12
??
60°
4. The area enclosed between the curves y = x|x| and
y = x – |x| is :
(1)
8
3
(2)
2
3
(3) 1 (4)
4
3
Ans. (4)
Sol.
y = 2x
y = x
2
y = 0
(0,0)
(–2,–4)
y = –x
2
0
2
2
A x 2x
?M ?] ?M ?M ??
4
3
?]
5. 60 words can be made using all the letters of the
word BHBJO, with or without meaning. If these
words are written as in a dictionary, then the 50
th
word is :
(1) OBBHJ (2) HBBJO
(3) OBBJH (4) JBBOH
Ans. (3)
Sol. B B H J O
B _____4! 24 ?]
4!
H _____ 12
2!
?]
4!
J _____ 12
2!
?]
O B B H J
O B B J H ?? 50
th
rank
6. Let
ˆˆ ˆ
a 2i 5j k ?] ?K ?M ,
ˆˆ ˆ
b 2i 2j 2k ?] ?M ?K
and c be three vectors such that
?H ?I ?H ?I ?H ?I ˆ ˆ ˆ
c i a b i a c i ?K ?? ?K ?K ?] ?? ?K
. a.c 29 ?]?M ,
then
?H ?I ˆˆ ˆ
c. 2i j k ?M ?K ?K is equal to :
(1) 10 (2) 5
(3) 15 (4) 12
Ans. (2)
Sol. Let's assume
ˆ
v a b i ?] ?K ?K
ˆˆ ˆ
5i 3j k ?] ?K ?K
and
ˆ
c i p ?K?]
So,
p v a p ?? ?] ??
p v p a 0 ?? ?K ?? ?]
?H ?I p v a 0 ?? ?K ?]
??
?H ?I p v a ?] ?? ?K
?H ?I ˆˆ
c i 7i 8j ?K ?] ?? ?K
?H ?I ˆ ˆ ˆ
a.c a.i a. 7i 8j ?K ?] ?? ?K
?H ?I 29 2 14 40 ?M ?K ?] ?? ?K
1
2
?? ?] ?M
?H ?I ?H ?I ?H ?I ?H ?I ˆ ˆ ˆ ˆ ˆ ˆ ˆ ˆ ˆ ˆ ˆ ˆ
c. 2i j k i. 2i j k 7i 8j . 2i j k ?M ?K ?K ?K ?M ?K ?K ?] ?? ?K ?M ?K ?K ?H ?I 1
14 8 2 5
2
?] ?M ?M ?K ?K ?]
7. Consider three vectors a,b,c . Let a 2, b 3 ?]?]
and a b c ?]?? . If 0,
3
?? ????
????
????
????
is the angle between
the vectors b and c , then the minimum value of
2
27 c a ?M is equal to :
(1) 110 (2) 105
(3) 124 (4) 121
Ans. (3)
Sol.
2 2
c a c a 2a.c ?M ?] ?K ?M
2
c 4 0 ?] ?K ?M
?q a b c ?]??
a b c ?]??
2 3 c sin ?]??
2
c cosec
3
?]?? 0,
3
?? ????
????
????
????
min
2 2
c
3
3
?]??
2
cosec ,
3
????
?? ?? ?? ?? ??????
??
2
min
16
27 c a 27 4 124
27
????
?M ?] ?K ?] ????
????
8. Let A(–1, 1) and B(2, 3) be two points and P be a
variable point above the line AB such that the area
of ?d PAB is 10. If the locus of P is ax + by = 15,
then 5a + 2b is :
(1)
12
5
?M (2)
6
5
?M
(3) 4 (4) 6
Ans. (1)
Sol.
P(h,k)
B(2,3)
A(–1,1)
h k 1
1
1 1 1 10
2
2 3 1
?M?]
–2x + 3y = 25
6 9
x y 15
5 5
?M ?K ?]
a =
6
5
?M , b =
9
5
5a = –6, 2b =
18
5
9. Let ( ?? , ?? , ?? ) be the point (8, 5, 7) in the line
x 1 y 1 z 2
2 3 5
?M ?K ?M ?]?] . Then ?? + ?? + ?? is equal to
(1) 16 (2) 18
(3) 14 (4) 20
Ans. (3)
Sol.
(2 ?? +1, 3 ?? – 1, 5 ?? + 2)
M
A'
A (8, 5, 7)
?H ?I ˆˆ ˆ
AM. 2i 3j 5k 0 ?K ?K ?]
(2 ?? – 7)(2) + (3 ?? – 6)(3) + (5 ?? – 5)(5) = 0
38 ?? = 57
3
2
???]
7 19
M 4, ,
2 2
????
????
????
A'(0,2,12)
10. If the constant term in the expansion of
12
5
3
3 2x
x
5
????
?K ????
????
????
, x ?? 0, is ?? ×2
8
×
5
3 , then 25 ?? is
equal to :
(1) 639 (2) 724
(3) 693 (4) 742
Ans. (3)
Sol.
12 r
r
1/5
12
r 1 r
1/3
3 2x
T C
x 5
?M ?K ????
????
?] ????
????
????
????
?H ?I ?H ?I ?H ?I ?H ?I 12 r
r 2r 12
12
5
r
r 1
r/3
C 3 2 x
T
5
?M ?M ?K ?]
r = 6
?H ?I ?H ?I 6/5 6
12
6 8 1/5
7
2
C 3 2
9 11 7
T 2 .3
25 5
???? ????
?]?]
????
????
25 ?? = 693
Page 4
FINAL JEE –MAIN EXAMINATION – APRIL, 2024
(Held On Friday 05
th
April, 2024) TIME : 3 : 00 PM to 6 : 00 PM
MATHEMATICS TEST PAPER WITH SOLUTION
SECTION-A
1. Let ƒ: [–1, 2] ?? R be given by
ƒ(x) = 2x
2
+ x + [x
2
] – [x], where [t] denotes the
greatest integer less than or equal to t. The number
of points, where ƒ is not continuous, is :
(1) 6 (2) 3
(3) 4 (4) 5
Ans. (3)
Sol. Doubtful points : –1, 0, 1, 2 , 3 , 2
at x = 2 , 3
?H ?I 2 2
Cont. Cont.
f(x) 2x x [x] x Discount
?? ?? ????
?] ?K ?M ?K ?]????
at x = –1 :
RHL f(x) (2 1 ( 1)) 0 2
Dis.
f( 1) 2 1 ( 1) 1 3
?? ?] ?M ?M ?M ?K ?] ?? ?? ?M ?] ?M ?M ?M ?K ?] ?? at x = 2 :
LHL f(x) 8 2 1 3 12
Cont.
f(2) 8 2 2 4 12
?? ?] ?K ?M ?K ?] ?? ?? ?] ?K ?M ?K ?] ?? at x = 0 :
LHL 0 0 ( 1) 0 1
Dis.
f(0) 0
?? ?K ?M ?M ?K ?] ?? ?? ?] ?? at x = 1
LHL 2 1 0 0 3
f(1) 3 1 1 3 Cont.
RHL 2 1 1 1 3
?? ?K ?M ?K ?] ?? ?? ?] ?M ?K ?] ?? ?? ?? ?K ?M ?K ?] ?? 2. The differential equation of the family of circles
passing the origin and having center at the line
y = x is :
(1) (x
2
– y
2
+ 2xy)dx = (x
2
– y
2
+ 2xy)dy
(2) (x
2
+ y
2
+ 2xy)dx = (x
2
+ y
2
– 2xy)dy
(3) (x
2
– y
2
+ 2xy)dx = (x
2
– y
2
– 2xy)dy
(4) (x
2
+ y
2
– 2xy)dx = (x
2
+ y
2
+ 2xy)dy
Ans. (3)
Sol. C ?? x
2
+ y
2
+ gx + gy = 0 .....(1)
2x + 2yy' + g + gy' = 0
2x 2yy'
g
1 y'
???? ?K ?]?M
????
?K????
Put in (1)
2 2
2x 2yy'
x y (x y) 0
1 y'
???? ?K ?K ?M ?K ?] ????
?K????
(x
2
– y
2
– 2xy)y' = x
2
– y
2
+ 2xy
3. Let S
1
= {z ?? C : |z| ?? 5},
2
z 1 3 i
S z C : Im 0
1 3 i
???? ????
?K?M ????
?] ?? ?? ???? ????
????
?M ???? ???? ????
and
S
3
= {z ?? C : Re (z) ?? ?@?P }. Then
(1)
125
6
?? (2)
125
24
?? (3)
125
4
?? (4)
125
12
?? Ans. (4)
Sol. S
1
: x
2
+ y
2
?? 25 .....(1)
S
2
: lm of
?H ?I ?H ?I z 1 3 i
0
1 3 i
?K?M
?? ?M lm of
x iy
1 0
1 3 i
????
?K ?K??
????
????
?M????
lm of
?H ?I ?H ?I x iy 1 3 i
0
4
????
?K?K
????
?? ????
????
?? 3 x y 0 ?K?? ......(2)
S
3
: x ?? 0 ......(3)
Area =
?H ?I 2
5
(5)
12
??
60°
4. The area enclosed between the curves y = x|x| and
y = x – |x| is :
(1)
8
3
(2)
2
3
(3) 1 (4)
4
3
Ans. (4)
Sol.
y = 2x
y = x
2
y = 0
(0,0)
(–2,–4)
y = –x
2
0
2
2
A x 2x
?M ?] ?M ?M ??
4
3
?]
5. 60 words can be made using all the letters of the
word BHBJO, with or without meaning. If these
words are written as in a dictionary, then the 50
th
word is :
(1) OBBHJ (2) HBBJO
(3) OBBJH (4) JBBOH
Ans. (3)
Sol. B B H J O
B _____4! 24 ?]
4!
H _____ 12
2!
?]
4!
J _____ 12
2!
?]
O B B H J
O B B J H ?? 50
th
rank
6. Let
ˆˆ ˆ
a 2i 5j k ?] ?K ?M ,
ˆˆ ˆ
b 2i 2j 2k ?] ?M ?K
and c be three vectors such that
?H ?I ?H ?I ?H ?I ˆ ˆ ˆ
c i a b i a c i ?K ?? ?K ?K ?] ?? ?K
. a.c 29 ?]?M ,
then
?H ?I ˆˆ ˆ
c. 2i j k ?M ?K ?K is equal to :
(1) 10 (2) 5
(3) 15 (4) 12
Ans. (2)
Sol. Let's assume
ˆ
v a b i ?] ?K ?K
ˆˆ ˆ
5i 3j k ?] ?K ?K
and
ˆ
c i p ?K?]
So,
p v a p ?? ?] ??
p v p a 0 ?? ?K ?? ?]
?H ?I p v a 0 ?? ?K ?]
??
?H ?I p v a ?] ?? ?K
?H ?I ˆˆ
c i 7i 8j ?K ?] ?? ?K
?H ?I ˆ ˆ ˆ
a.c a.i a. 7i 8j ?K ?] ?? ?K
?H ?I 29 2 14 40 ?M ?K ?] ?? ?K
1
2
?? ?] ?M
?H ?I ?H ?I ?H ?I ?H ?I ˆ ˆ ˆ ˆ ˆ ˆ ˆ ˆ ˆ ˆ ˆ ˆ
c. 2i j k i. 2i j k 7i 8j . 2i j k ?M ?K ?K ?K ?M ?K ?K ?] ?? ?K ?M ?K ?K ?H ?I 1
14 8 2 5
2
?] ?M ?M ?K ?K ?]
7. Consider three vectors a,b,c . Let a 2, b 3 ?]?]
and a b c ?]?? . If 0,
3
?? ????
????
????
????
is the angle between
the vectors b and c , then the minimum value of
2
27 c a ?M is equal to :
(1) 110 (2) 105
(3) 124 (4) 121
Ans. (3)
Sol.
2 2
c a c a 2a.c ?M ?] ?K ?M
2
c 4 0 ?] ?K ?M
?q a b c ?]??
a b c ?]??
2 3 c sin ?]??
2
c cosec
3
?]?? 0,
3
?? ????
????
????
????
min
2 2
c
3
3
?]??
2
cosec ,
3
????
?? ?? ?? ?? ??????
??
2
min
16
27 c a 27 4 124
27
????
?M ?] ?K ?] ????
????
8. Let A(–1, 1) and B(2, 3) be two points and P be a
variable point above the line AB such that the area
of ?d PAB is 10. If the locus of P is ax + by = 15,
then 5a + 2b is :
(1)
12
5
?M (2)
6
5
?M
(3) 4 (4) 6
Ans. (1)
Sol.
P(h,k)
B(2,3)
A(–1,1)
h k 1
1
1 1 1 10
2
2 3 1
?M?]
–2x + 3y = 25
6 9
x y 15
5 5
?M ?K ?]
a =
6
5
?M , b =
9
5
5a = –6, 2b =
18
5
9. Let ( ?? , ?? , ?? ) be the point (8, 5, 7) in the line
x 1 y 1 z 2
2 3 5
?M ?K ?M ?]?] . Then ?? + ?? + ?? is equal to
(1) 16 (2) 18
(3) 14 (4) 20
Ans. (3)
Sol.
(2 ?? +1, 3 ?? – 1, 5 ?? + 2)
M
A'
A (8, 5, 7)
?H ?I ˆˆ ˆ
AM. 2i 3j 5k 0 ?K ?K ?]
(2 ?? – 7)(2) + (3 ?? – 6)(3) + (5 ?? – 5)(5) = 0
38 ?? = 57
3
2
???]
7 19
M 4, ,
2 2
????
????
????
A'(0,2,12)
10. If the constant term in the expansion of
12
5
3
3 2x
x
5
????
?K ????
????
????
, x ?? 0, is ?? ×2
8
×
5
3 , then 25 ?? is
equal to :
(1) 639 (2) 724
(3) 693 (4) 742
Ans. (3)
Sol.
12 r
r
1/5
12
r 1 r
1/3
3 2x
T C
x 5
?M ?K ????
????
?] ????
????
????
????
?H ?I ?H ?I ?H ?I ?H ?I 12 r
r 2r 12
12
5
r
r 1
r/3
C 3 2 x
T
5
?M ?M ?K ?]
r = 6
?H ?I ?H ?I 6/5 6
12
6 8 1/5
7
2
C 3 2
9 11 7
T 2 .3
25 5
???? ????
?]?]
????
????
25 ?? = 693
11. Let ƒ, g : R ?? R be defined as : ƒ(x) = |x – 1| and
x
e , x 0
g(x)
x 1, x 0
?? ?? ?? ?] ?? ?K?? ?? ?? . Then the function ƒ(g(x)) is
(1) neither one-one nor onto.
(2) one-one but not onto.
(3) both one-one and onto.
(4) onto but not one-one.
Ans. (1)
Sol. f(g(x)) = |g(x) – 1|
x
e 1 x 0
fog
x 1 1 x 0
?? ?M??
?? ?? ?K ?M ?? ??
x
e 1 x 0
fog
x x 0
?? ?M??
???M??
??
12. Let the circle C
1
: x
2
+ y
2
– 2(x + y) + 1 = 0 and C
2
be a circle having centre at (–1, 0) and radius 2. If
the line of the common chord of C
1
and C
2
intersects the y-axis at the point P, then the square
of the distance of P from the centre of C
1
is :
(1) 2 (2) 1
(3) 6 (4) 4
Ans. (1)
Sol. S
1
: x
2
+ y
2
– 2x – 2y + 1 = 0
S
2
: x
2
+ y
2
+ 2x – 3 = 0
Common chord = S
1
– S
2
= 0
–4x – 2y + 4 = 0
2x + y = 2 ?? P(0, 2)
2
(c,p)
d = (1 – 0)
2
+ (2 – 1)
2
= 2
13. Let the set S = {2, 4, 8, 16, ....., 512} be partitioned
into 3 sets A, B, C with equal number of elements such
that A ?? B ?? C = S and A ?? B = B ?? C = A ?? C = ?? .
The maximum number of such possible partitions of S
is equal to :
(1) 1680 (2) 1520
(3) 1710 (4) 1640
Ans. (1)
Sol.
A
B
C
?H ?I 9!
3!
3!3!3! 3!
??
14. The values of m, n, for which the system of
equations
x + y + z = 4,
2x + 5y + 5z = 17,
x + 2y + mz = n
has infinitely many solutions, satisfy the equation :
(1) m
2
+ n
2
– m – n = 46
(2) m
2
+ n
2
+ m + n = 64
(3) m
2
+ n
2
+ mn = 68
(4) m
2
+ n
2
– mn = 39
Ans. (4)
Sol.
1 1 1
D 2 5 5 0
1 2 m
?]?] ?? m = 2
3
1 1 4
D 2 5 17 0
1 2 n
?]?]
?? n = 7
15. The coefficients a, b, c in the quadratic equation
ax
2
+ bx + c = 0 are from the set {1, 2, 3, 4, 5, 6}.
If the probability of this equation having one real
root bigger than the other is p, then 216p equals :
(1) 57 (2) 38
(3) 19 (4) 76
Ans. (2)
Page 5
FINAL JEE –MAIN EXAMINATION – APRIL, 2024
(Held On Friday 05
th
April, 2024) TIME : 3 : 00 PM to 6 : 00 PM
MATHEMATICS TEST PAPER WITH SOLUTION
SECTION-A
1. Let ƒ: [–1, 2] ?? R be given by
ƒ(x) = 2x
2
+ x + [x
2
] – [x], where [t] denotes the
greatest integer less than or equal to t. The number
of points, where ƒ is not continuous, is :
(1) 6 (2) 3
(3) 4 (4) 5
Ans. (3)
Sol. Doubtful points : –1, 0, 1, 2 , 3 , 2
at x = 2 , 3
?H ?I 2 2
Cont. Cont.
f(x) 2x x [x] x Discount
?? ?? ????
?] ?K ?M ?K ?]????
at x = –1 :
RHL f(x) (2 1 ( 1)) 0 2
Dis.
f( 1) 2 1 ( 1) 1 3
?? ?] ?M ?M ?M ?K ?] ?? ?? ?M ?] ?M ?M ?M ?K ?] ?? at x = 2 :
LHL f(x) 8 2 1 3 12
Cont.
f(2) 8 2 2 4 12
?? ?] ?K ?M ?K ?] ?? ?? ?] ?K ?M ?K ?] ?? at x = 0 :
LHL 0 0 ( 1) 0 1
Dis.
f(0) 0
?? ?K ?M ?M ?K ?] ?? ?? ?] ?? at x = 1
LHL 2 1 0 0 3
f(1) 3 1 1 3 Cont.
RHL 2 1 1 1 3
?? ?K ?M ?K ?] ?? ?? ?] ?M ?K ?] ?? ?? ?? ?K ?M ?K ?] ?? 2. The differential equation of the family of circles
passing the origin and having center at the line
y = x is :
(1) (x
2
– y
2
+ 2xy)dx = (x
2
– y
2
+ 2xy)dy
(2) (x
2
+ y
2
+ 2xy)dx = (x
2
+ y
2
– 2xy)dy
(3) (x
2
– y
2
+ 2xy)dx = (x
2
– y
2
– 2xy)dy
(4) (x
2
+ y
2
– 2xy)dx = (x
2
+ y
2
+ 2xy)dy
Ans. (3)
Sol. C ?? x
2
+ y
2
+ gx + gy = 0 .....(1)
2x + 2yy' + g + gy' = 0
2x 2yy'
g
1 y'
???? ?K ?]?M
????
?K????
Put in (1)
2 2
2x 2yy'
x y (x y) 0
1 y'
???? ?K ?K ?M ?K ?] ????
?K????
(x
2
– y
2
– 2xy)y' = x
2
– y
2
+ 2xy
3. Let S
1
= {z ?? C : |z| ?? 5},
2
z 1 3 i
S z C : Im 0
1 3 i
???? ????
?K?M ????
?] ?? ?? ???? ????
????
?M ???? ???? ????
and
S
3
= {z ?? C : Re (z) ?? ?@?P }. Then
(1)
125
6
?? (2)
125
24
?? (3)
125
4
?? (4)
125
12
?? Ans. (4)
Sol. S
1
: x
2
+ y
2
?? 25 .....(1)
S
2
: lm of
?H ?I ?H ?I z 1 3 i
0
1 3 i
?K?M
?? ?M lm of
x iy
1 0
1 3 i
????
?K ?K??
????
????
?M????
lm of
?H ?I ?H ?I x iy 1 3 i
0
4
????
?K?K
????
?? ????
????
?? 3 x y 0 ?K?? ......(2)
S
3
: x ?? 0 ......(3)
Area =
?H ?I 2
5
(5)
12
??
60°
4. The area enclosed between the curves y = x|x| and
y = x – |x| is :
(1)
8
3
(2)
2
3
(3) 1 (4)
4
3
Ans. (4)
Sol.
y = 2x
y = x
2
y = 0
(0,0)
(–2,–4)
y = –x
2
0
2
2
A x 2x
?M ?] ?M ?M ??
4
3
?]
5. 60 words can be made using all the letters of the
word BHBJO, with or without meaning. If these
words are written as in a dictionary, then the 50
th
word is :
(1) OBBHJ (2) HBBJO
(3) OBBJH (4) JBBOH
Ans. (3)
Sol. B B H J O
B _____4! 24 ?]
4!
H _____ 12
2!
?]
4!
J _____ 12
2!
?]
O B B H J
O B B J H ?? 50
th
rank
6. Let
ˆˆ ˆ
a 2i 5j k ?] ?K ?M ,
ˆˆ ˆ
b 2i 2j 2k ?] ?M ?K
and c be three vectors such that
?H ?I ?H ?I ?H ?I ˆ ˆ ˆ
c i a b i a c i ?K ?? ?K ?K ?] ?? ?K
. a.c 29 ?]?M ,
then
?H ?I ˆˆ ˆ
c. 2i j k ?M ?K ?K is equal to :
(1) 10 (2) 5
(3) 15 (4) 12
Ans. (2)
Sol. Let's assume
ˆ
v a b i ?] ?K ?K
ˆˆ ˆ
5i 3j k ?] ?K ?K
and
ˆ
c i p ?K?]
So,
p v a p ?? ?] ??
p v p a 0 ?? ?K ?? ?]
?H ?I p v a 0 ?? ?K ?]
??
?H ?I p v a ?] ?? ?K
?H ?I ˆˆ
c i 7i 8j ?K ?] ?? ?K
?H ?I ˆ ˆ ˆ
a.c a.i a. 7i 8j ?K ?] ?? ?K
?H ?I 29 2 14 40 ?M ?K ?] ?? ?K
1
2
?? ?] ?M
?H ?I ?H ?I ?H ?I ?H ?I ˆ ˆ ˆ ˆ ˆ ˆ ˆ ˆ ˆ ˆ ˆ ˆ
c. 2i j k i. 2i j k 7i 8j . 2i j k ?M ?K ?K ?K ?M ?K ?K ?] ?? ?K ?M ?K ?K ?H ?I 1
14 8 2 5
2
?] ?M ?M ?K ?K ?]
7. Consider three vectors a,b,c . Let a 2, b 3 ?]?]
and a b c ?]?? . If 0,
3
?? ????
????
????
????
is the angle between
the vectors b and c , then the minimum value of
2
27 c a ?M is equal to :
(1) 110 (2) 105
(3) 124 (4) 121
Ans. (3)
Sol.
2 2
c a c a 2a.c ?M ?] ?K ?M
2
c 4 0 ?] ?K ?M
?q a b c ?]??
a b c ?]??
2 3 c sin ?]??
2
c cosec
3
?]?? 0,
3
?? ????
????
????
????
min
2 2
c
3
3
?]??
2
cosec ,
3
????
?? ?? ?? ?? ??????
??
2
min
16
27 c a 27 4 124
27
????
?M ?] ?K ?] ????
????
8. Let A(–1, 1) and B(2, 3) be two points and P be a
variable point above the line AB such that the area
of ?d PAB is 10. If the locus of P is ax + by = 15,
then 5a + 2b is :
(1)
12
5
?M (2)
6
5
?M
(3) 4 (4) 6
Ans. (1)
Sol.
P(h,k)
B(2,3)
A(–1,1)
h k 1
1
1 1 1 10
2
2 3 1
?M?]
–2x + 3y = 25
6 9
x y 15
5 5
?M ?K ?]
a =
6
5
?M , b =
9
5
5a = –6, 2b =
18
5
9. Let ( ?? , ?? , ?? ) be the point (8, 5, 7) in the line
x 1 y 1 z 2
2 3 5
?M ?K ?M ?]?] . Then ?? + ?? + ?? is equal to
(1) 16 (2) 18
(3) 14 (4) 20
Ans. (3)
Sol.
(2 ?? +1, 3 ?? – 1, 5 ?? + 2)
M
A'
A (8, 5, 7)
?H ?I ˆˆ ˆ
AM. 2i 3j 5k 0 ?K ?K ?]
(2 ?? – 7)(2) + (3 ?? – 6)(3) + (5 ?? – 5)(5) = 0
38 ?? = 57
3
2
???]
7 19
M 4, ,
2 2
????
????
????
A'(0,2,12)
10. If the constant term in the expansion of
12
5
3
3 2x
x
5
????
?K ????
????
????
, x ?? 0, is ?? ×2
8
×
5
3 , then 25 ?? is
equal to :
(1) 639 (2) 724
(3) 693 (4) 742
Ans. (3)
Sol.
12 r
r
1/5
12
r 1 r
1/3
3 2x
T C
x 5
?M ?K ????
????
?] ????
????
????
????
?H ?I ?H ?I ?H ?I ?H ?I 12 r
r 2r 12
12
5
r
r 1
r/3
C 3 2 x
T
5
?M ?M ?K ?]
r = 6
?H ?I ?H ?I 6/5 6
12
6 8 1/5
7
2
C 3 2
9 11 7
T 2 .3
25 5
???? ????
?]?]
????
????
25 ?? = 693
11. Let ƒ, g : R ?? R be defined as : ƒ(x) = |x – 1| and
x
e , x 0
g(x)
x 1, x 0
?? ?? ?? ?] ?? ?K?? ?? ?? . Then the function ƒ(g(x)) is
(1) neither one-one nor onto.
(2) one-one but not onto.
(3) both one-one and onto.
(4) onto but not one-one.
Ans. (1)
Sol. f(g(x)) = |g(x) – 1|
x
e 1 x 0
fog
x 1 1 x 0
?? ?M??
?? ?? ?K ?M ?? ??
x
e 1 x 0
fog
x x 0
?? ?M??
???M??
??
12. Let the circle C
1
: x
2
+ y
2
– 2(x + y) + 1 = 0 and C
2
be a circle having centre at (–1, 0) and radius 2. If
the line of the common chord of C
1
and C
2
intersects the y-axis at the point P, then the square
of the distance of P from the centre of C
1
is :
(1) 2 (2) 1
(3) 6 (4) 4
Ans. (1)
Sol. S
1
: x
2
+ y
2
– 2x – 2y + 1 = 0
S
2
: x
2
+ y
2
+ 2x – 3 = 0
Common chord = S
1
– S
2
= 0
–4x – 2y + 4 = 0
2x + y = 2 ?? P(0, 2)
2
(c,p)
d = (1 – 0)
2
+ (2 – 1)
2
= 2
13. Let the set S = {2, 4, 8, 16, ....., 512} be partitioned
into 3 sets A, B, C with equal number of elements such
that A ?? B ?? C = S and A ?? B = B ?? C = A ?? C = ?? .
The maximum number of such possible partitions of S
is equal to :
(1) 1680 (2) 1520
(3) 1710 (4) 1640
Ans. (1)
Sol.
A
B
C
?H ?I 9!
3!
3!3!3! 3!
??
14. The values of m, n, for which the system of
equations
x + y + z = 4,
2x + 5y + 5z = 17,
x + 2y + mz = n
has infinitely many solutions, satisfy the equation :
(1) m
2
+ n
2
– m – n = 46
(2) m
2
+ n
2
+ m + n = 64
(3) m
2
+ n
2
+ mn = 68
(4) m
2
+ n
2
– mn = 39
Ans. (4)
Sol.
1 1 1
D 2 5 5 0
1 2 m
?]?] ?? m = 2
3
1 1 4
D 2 5 17 0
1 2 n
?]?]
?? n = 7
15. The coefficients a, b, c in the quadratic equation
ax
2
+ bx + c = 0 are from the set {1, 2, 3, 4, 5, 6}.
If the probability of this equation having one real
root bigger than the other is p, then 216p equals :
(1) 57 (2) 38
(3) 19 (4) 76
Ans. (2)
Sol. D > 0
b
2
> 4ac
b = 3 : (a, c) = (1, 1)(1, 2)(2,1)
b = 4 : (a, c) = (1, 1)(1, 2)(2,1)(1,3)(3,1)
b = 5 : (a, c) = (1,1)(1,2)(2,1) (1,3)(3,1)(1,4)(4,1)
(1,5)(5,1)(1,6)(6,1)(2,3)(3,2)(2,2)
b = 6 : (a, c) = (1,1)(1,2)(2,1) (1,3)(3,1)(1,4)(4,1)
(1,5)(5,1)(1,6)(6,1)(2,3)(3,2)(2,4)(4,2)(2,2)
fav. cases = 38
Prob. :
38
6 6 6 ????
16. Let ABCD and AEFG be squares of side 4 and
2 units, respectively. The point E is on the line
segment AB and the point F is on the diagonal AC.
Then the radius r of the circle passing through the
point F and touching the line segments BC and CD
satisfies :
(1) r = 1 (2) r
2
– 8r + 8 = 0
(3) 2r
2
– 4r + 1 = 0 (4) 2r
2
– 8r + 7 = 0
Ans. (2)
Sol.
A B
E
C D
(0, 4) (4, 4)
(4, 0)
(2, 0) (0, 0)
F(2,2)
r
r
r
o
x = 4
F
(2,2)
y = 4
(4–r, 4–r )
OF
2
= r
2
(2 – r)
2
+ (2 – r)
2
= r
2
r
2
– 8r + 8 = 0
17. Let ?? (m, n) =
1
m 1 n 1
0
x (1 x) dx
?M?M
?M ?? , m, n > 0. If
1
10 20
0
(1 x ) dx a (b,c) ?M ?] ?? ?? ?? , then 100(a + b + x)
equals ______.
(1) 1021 (2) 1120
(3) 2012 (4) 2120
Ans. (4)
Sol.
?H ?I 1
20
10
0
I 1. 1 x dx ?]?M
??
x
10
= t
x = t
1/10
?H ?I 9/10 1
dx t dt
10
?M ?]
?H ?I 1
9/10
20
0
1
I (1 t) t dt
10
?M ?]?M
??
?H ?I 1
20
9/10
0
1
I t 1 t dt
10
?M ?]?M
??
a =
1
10
b =
1
10
c = 21
18. Let ???? ?? 0 and
3
A
2
????????
????
?] ?? ?? ?? ????
???? ?? ?M ?? ?? ????
.
If
3 9 3
B 7 2
2 5 2
?? ?M ?? ????
????
?] ?M ?? ?M ?? ????
???? ?M ?? ?M ?? ????
is the matrix of cofactors
of the elements of A, then det(AB) is equal to :
(1) 343 (2) 125
(3) 64 (4) 216
Ans. (4)
Sol. Equating co-factor fo A
21
(2 ?? 2
– 3 ?? ) = ??
?? = 0, 2 (accept)
Now, 2 ?? 2
– ???? = 3 ??
?? = 2 ?? = 1
|AB| = |A cof (A)| = |A|
3
1 2 3
A 2 2 1 6 2(9) 3(6) 6
1 2 4
?] ?] ?M ?K ?] ?M
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