Page 1
1
JEE–MAIN EXAMINATION – JANUARY 2025
MATHEMATICS TEST PAPER WITH SOLUTION
(HELD ON WEDNESDAY 22
nd
JANUARY 2025) TIME : 9:00 AM TO 12:00 NOON
SECTION-A
1. The number of non-empty equivalence relations on
the set {1,2,3} is :
(1) 6 (2) 7
(3) 5 (4) 4
Ans. (3)
Sol. Let R be the required relation
A = {(1, 1) (2, 2), (3, 3)}
(i) | R | = 3, when R = A
(ii) | R | = 5, e.g. R = A ? {(1, 2), (2, 1)}
Number of R can be [3]
(iii) R = {1, 2, 3} × {1, 2, 3}
Ans. (5)
2. Let ƒ : R ?R be a twice differentiable function
such that ƒ(x + y) = ƒ(x) ƒ(y) for all x, y ? R. If
ƒ'(0) = 4a and ƒ staisfies ƒ''(x) – 3a ƒ'(x) – ƒ(x) = 0,
a > 0, then the area of the region
R = {(x,y) | 0 ? y ? ƒ(ax), 0 ? x ? 2} is :
(1) e
2
– 1 (2) e
4
+ 1
(3) e
4
– 1 (4) e
2
+ 1
Ans. (1)
Sol. f(x + y) = f(x).f(y)
? f(x) = e
?x
f ?(0) = 4a
? f ?(x) = ?e
?x
? ? = 4a
So, f(x) = e
4ax
f ??(x) – 3af ?(x) – f (x) = 0
? ?
2
– 3a ? – 1 = 0
? 16a
2
– 12a
2
– 1 = 0 ? 4a
2
= 1 ? ?
1
a
2
?
x = 0
x = 2
f(ax) = e
x
F(x) = e
2x
2
x2
0
Area e dx e 1 ? ? ?
?
3. Let the triangle PQR be the image of the
triangle with vertices (1,3), (3,1) and (2, 4) in
the line x + 2y = 2. If the centroid of ?PQR is
the point ( ?, ?), then 15( ? – ?) is equal to :
(1) 24 (2) 19
(3) 21 (4) 22
Ans. (4)
Sol. Let ‘G’ be the centroid of ? formed by (1, 3) (3, 1)
& (2, 4)
8
G 2,
3
??
?
??
??
Image of G w.r.t. x + 2y – 2 = 0
16
8
22
2 3
3
2
1 2 1 4
??
??
?? ??
??
??
? ? ?
?
2 16
53
? ??
?
??
??
?
32 2
2
15 15
??
? ? ? ? ,
32 2 8 24
15 3 15
? ? ?
? ? ? ?
15( ? – ?) = – 2 + 24 = 22
4. Let z
1
, z
2
and z
3
be three complex numbers on the circle
|z| = 1 with
??
?
1
arg(z )
4
, arg(z
2
) = 0 and
?
?
3
arg(z )
4
.
If ? ? ? ? ? ?
2
1 2 2 3 3 1
z z z z z z 2 , ?, ? ? Z, then the
value of ?
2
+ ?
2
is :
(1) 24 (2) 41
(3) 31 (4) 29
Ans. (4)
Sol. Z
1
= e
–i ?/4
, Z
2
= 1, Z
3
= e
i ?/4
2
1 2 2 3 3 1
z z z z z z ?? =
2
i i i i
4 4 4 4
e 1 1 e e e
? ? ? ?
??
? ? ? ? ?
2
i i i
4 4 4
eee
? ? ?
??
??
2
i
4
2e i
?
?
?? =
2
2 2i i ? ? ?
=
? ? ? ?
22
2 1 2 ?? = 2 + 1 + 2 – 2 2 = 5 – 22
? = 5, ? = –2
? ?
2
+ ?
2
= 29
Page 2
1
JEE–MAIN EXAMINATION – JANUARY 2025
MATHEMATICS TEST PAPER WITH SOLUTION
(HELD ON WEDNESDAY 22
nd
JANUARY 2025) TIME : 9:00 AM TO 12:00 NOON
SECTION-A
1. The number of non-empty equivalence relations on
the set {1,2,3} is :
(1) 6 (2) 7
(3) 5 (4) 4
Ans. (3)
Sol. Let R be the required relation
A = {(1, 1) (2, 2), (3, 3)}
(i) | R | = 3, when R = A
(ii) | R | = 5, e.g. R = A ? {(1, 2), (2, 1)}
Number of R can be [3]
(iii) R = {1, 2, 3} × {1, 2, 3}
Ans. (5)
2. Let ƒ : R ?R be a twice differentiable function
such that ƒ(x + y) = ƒ(x) ƒ(y) for all x, y ? R. If
ƒ'(0) = 4a and ƒ staisfies ƒ''(x) – 3a ƒ'(x) – ƒ(x) = 0,
a > 0, then the area of the region
R = {(x,y) | 0 ? y ? ƒ(ax), 0 ? x ? 2} is :
(1) e
2
– 1 (2) e
4
+ 1
(3) e
4
– 1 (4) e
2
+ 1
Ans. (1)
Sol. f(x + y) = f(x).f(y)
? f(x) = e
?x
f ?(0) = 4a
? f ?(x) = ?e
?x
? ? = 4a
So, f(x) = e
4ax
f ??(x) – 3af ?(x) – f (x) = 0
? ?
2
– 3a ? – 1 = 0
? 16a
2
– 12a
2
– 1 = 0 ? 4a
2
= 1 ? ?
1
a
2
?
x = 0
x = 2
f(ax) = e
x
F(x) = e
2x
2
x2
0
Area e dx e 1 ? ? ?
?
3. Let the triangle PQR be the image of the
triangle with vertices (1,3), (3,1) and (2, 4) in
the line x + 2y = 2. If the centroid of ?PQR is
the point ( ?, ?), then 15( ? – ?) is equal to :
(1) 24 (2) 19
(3) 21 (4) 22
Ans. (4)
Sol. Let ‘G’ be the centroid of ? formed by (1, 3) (3, 1)
& (2, 4)
8
G 2,
3
??
?
??
??
Image of G w.r.t. x + 2y – 2 = 0
16
8
22
2 3
3
2
1 2 1 4
??
??
?? ??
??
??
? ? ?
?
2 16
53
? ??
?
??
??
?
32 2
2
15 15
??
? ? ? ? ,
32 2 8 24
15 3 15
? ? ?
? ? ? ?
15( ? – ?) = – 2 + 24 = 22
4. Let z
1
, z
2
and z
3
be three complex numbers on the circle
|z| = 1 with
??
?
1
arg(z )
4
, arg(z
2
) = 0 and
?
?
3
arg(z )
4
.
If ? ? ? ? ? ?
2
1 2 2 3 3 1
z z z z z z 2 , ?, ? ? Z, then the
value of ?
2
+ ?
2
is :
(1) 24 (2) 41
(3) 31 (4) 29
Ans. (4)
Sol. Z
1
= e
–i ?/4
, Z
2
= 1, Z
3
= e
i ?/4
2
1 2 2 3 3 1
z z z z z z ?? =
2
i i i i
4 4 4 4
e 1 1 e e e
? ? ? ?
??
? ? ? ? ?
2
i i i
4 4 4
eee
? ? ?
??
??
2
i
4
2e i
?
?
?? =
2
2 2i i ? ? ?
=
? ? ? ?
22
2 1 2 ?? = 2 + 1 + 2 – 2 2 = 5 – 22
? = 5, ? = –2
? ?
2
+ ?
2
= 29
2
5. Using the principal values of the inverse
trigonometric functions the sum of the maximum
and the minimum values of 16((sec
–1
x)
2
+ (cosec
–1
x)
2
)
is :
(1) 24 ?
2
(2) 18 ?
2
(3) 31 ?
2
(4) 22 ?
2
Ans. (4)
Sol. 16(sec
–1
x)
2
+ (cosec
–1
x)
2
Sec
–1
x = a ?[0, ?] –
2
? ??
??
??
cosec
–1
x = a
2
?
?
=
2
2
22
16 a a 16 2a a
24
??
?? ?? ??
? ? ? ? ? ?
??
?? ??
??
????
??
max]
a =
?
= 16[2 ?
2
– ?
2
+
2
4
? ] = 20 ?
2
a
4
min]
?
?
=
2 2 2
2
2
16 2
16 4 4
?? ? ? ? ?
? ? ? ?
??
??
Sum = 22 ?
2
6. A coin is tossed three times. Let X denote the
number of times a tail follows a head. If ? and ?
2
denote the mean and variance of X, then the value
of 64( ? + ?
2
) is :
(1) 51 (2) 48
(3) 32 (4) 64
Ans. (2)
Sol. HHH ? 0
HHT ? 0
HTH ? 1
HTT ? 0
THH ? 1
THT ? 1
TTH ? 1
TTT ? 0
Probability distribution
i
i
x 0 1
11
P(x )
22
ii
1
xp
2
? ? ?
?
2 2 2
ii
x p µ ? ? ?
?
1 1 1
2 4 4
???
64(µ + ?
2
) =
11
64
24
??
?
??
??
= 48
7. Let a
1
, a
2
, a
3
..... be a G.P. of increasing positive
terms. If a
1
a
5
= 28 and a
2
+ a
4
= 29, the a
6
is equal to
(1) 628 (2) 526
(3) 784 (4) 812
Ans. (3)
Sol. a
1
.a
5
= 28 ? a.ar
4
= 28 ? a
2
r
4
= 28 …(1)
a
2
+ a
4
= 29 ? ar + ar
3
= 29
? ar(1 + r
2
) = 29
? a
2
r
2
(1 + r
2
)
2
= (29)
2
…(2)
By Eq. (1) & (2)
2
22
r 28
(1 r ) 29 29
?
??
?
2
r 28
1 r 29
?
?
? r 28 ?
? a
2
r
4
= 28 ? a
2
× (28)
2
= 28
?
1
a
28
?
? a
6
= ar
5
=
2
1
(28) 28 784
28
??
8. Let
? ? ?
??
1
x 1 y 2 z 3
L:
2 3 4
and
? ? ?
??
2
x 2 y 4 z 5
L:
3 4 5
be two lines. Then which
of the following points lies on the line of the
shortest distance between L
1
and L
2
?
(1)
??
??
??
??
5
, 7,1
3
(2)
??
??
??
1
2,3,
3
(3)
??
?
??
??
81
, 1,
33
(4)
??
?
??
??
14 22
, 3,
33
Ans. (4)
Sol.
P
Q
L
1
L
2
P(2 ? + 1, 3 ? + 2, 4 ? + 3) on L
1
Q(3µ + 2, 4µ + 4, 5µ + 5) on L
2
Dr’s of PQ = 3µ – 2 ? + 1, 4µ – 3? + 2, 5µ – 4 ? + 2
PQ ? L
1
Page 3
1
JEE–MAIN EXAMINATION – JANUARY 2025
MATHEMATICS TEST PAPER WITH SOLUTION
(HELD ON WEDNESDAY 22
nd
JANUARY 2025) TIME : 9:00 AM TO 12:00 NOON
SECTION-A
1. The number of non-empty equivalence relations on
the set {1,2,3} is :
(1) 6 (2) 7
(3) 5 (4) 4
Ans. (3)
Sol. Let R be the required relation
A = {(1, 1) (2, 2), (3, 3)}
(i) | R | = 3, when R = A
(ii) | R | = 5, e.g. R = A ? {(1, 2), (2, 1)}
Number of R can be [3]
(iii) R = {1, 2, 3} × {1, 2, 3}
Ans. (5)
2. Let ƒ : R ?R be a twice differentiable function
such that ƒ(x + y) = ƒ(x) ƒ(y) for all x, y ? R. If
ƒ'(0) = 4a and ƒ staisfies ƒ''(x) – 3a ƒ'(x) – ƒ(x) = 0,
a > 0, then the area of the region
R = {(x,y) | 0 ? y ? ƒ(ax), 0 ? x ? 2} is :
(1) e
2
– 1 (2) e
4
+ 1
(3) e
4
– 1 (4) e
2
+ 1
Ans. (1)
Sol. f(x + y) = f(x).f(y)
? f(x) = e
?x
f ?(0) = 4a
? f ?(x) = ?e
?x
? ? = 4a
So, f(x) = e
4ax
f ??(x) – 3af ?(x) – f (x) = 0
? ?
2
– 3a ? – 1 = 0
? 16a
2
– 12a
2
– 1 = 0 ? 4a
2
= 1 ? ?
1
a
2
?
x = 0
x = 2
f(ax) = e
x
F(x) = e
2x
2
x2
0
Area e dx e 1 ? ? ?
?
3. Let the triangle PQR be the image of the
triangle with vertices (1,3), (3,1) and (2, 4) in
the line x + 2y = 2. If the centroid of ?PQR is
the point ( ?, ?), then 15( ? – ?) is equal to :
(1) 24 (2) 19
(3) 21 (4) 22
Ans. (4)
Sol. Let ‘G’ be the centroid of ? formed by (1, 3) (3, 1)
& (2, 4)
8
G 2,
3
??
?
??
??
Image of G w.r.t. x + 2y – 2 = 0
16
8
22
2 3
3
2
1 2 1 4
??
??
?? ??
??
??
? ? ?
?
2 16
53
? ??
?
??
??
?
32 2
2
15 15
??
? ? ? ? ,
32 2 8 24
15 3 15
? ? ?
? ? ? ?
15( ? – ?) = – 2 + 24 = 22
4. Let z
1
, z
2
and z
3
be three complex numbers on the circle
|z| = 1 with
??
?
1
arg(z )
4
, arg(z
2
) = 0 and
?
?
3
arg(z )
4
.
If ? ? ? ? ? ?
2
1 2 2 3 3 1
z z z z z z 2 , ?, ? ? Z, then the
value of ?
2
+ ?
2
is :
(1) 24 (2) 41
(3) 31 (4) 29
Ans. (4)
Sol. Z
1
= e
–i ?/4
, Z
2
= 1, Z
3
= e
i ?/4
2
1 2 2 3 3 1
z z z z z z ?? =
2
i i i i
4 4 4 4
e 1 1 e e e
? ? ? ?
??
? ? ? ? ?
2
i i i
4 4 4
eee
? ? ?
??
??
2
i
4
2e i
?
?
?? =
2
2 2i i ? ? ?
=
? ? ? ?
22
2 1 2 ?? = 2 + 1 + 2 – 2 2 = 5 – 22
? = 5, ? = –2
? ?
2
+ ?
2
= 29
2
5. Using the principal values of the inverse
trigonometric functions the sum of the maximum
and the minimum values of 16((sec
–1
x)
2
+ (cosec
–1
x)
2
)
is :
(1) 24 ?
2
(2) 18 ?
2
(3) 31 ?
2
(4) 22 ?
2
Ans. (4)
Sol. 16(sec
–1
x)
2
+ (cosec
–1
x)
2
Sec
–1
x = a ?[0, ?] –
2
? ??
??
??
cosec
–1
x = a
2
?
?
=
2
2
22
16 a a 16 2a a
24
??
?? ?? ??
? ? ? ? ? ?
??
?? ??
??
????
??
max]
a =
?
= 16[2 ?
2
– ?
2
+
2
4
? ] = 20 ?
2
a
4
min]
?
?
=
2 2 2
2
2
16 2
16 4 4
?? ? ? ? ?
? ? ? ?
??
??
Sum = 22 ?
2
6. A coin is tossed three times. Let X denote the
number of times a tail follows a head. If ? and ?
2
denote the mean and variance of X, then the value
of 64( ? + ?
2
) is :
(1) 51 (2) 48
(3) 32 (4) 64
Ans. (2)
Sol. HHH ? 0
HHT ? 0
HTH ? 1
HTT ? 0
THH ? 1
THT ? 1
TTH ? 1
TTT ? 0
Probability distribution
i
i
x 0 1
11
P(x )
22
ii
1
xp
2
? ? ?
?
2 2 2
ii
x p µ ? ? ?
?
1 1 1
2 4 4
???
64(µ + ?
2
) =
11
64
24
??
?
??
??
= 48
7. Let a
1
, a
2
, a
3
..... be a G.P. of increasing positive
terms. If a
1
a
5
= 28 and a
2
+ a
4
= 29, the a
6
is equal to
(1) 628 (2) 526
(3) 784 (4) 812
Ans. (3)
Sol. a
1
.a
5
= 28 ? a.ar
4
= 28 ? a
2
r
4
= 28 …(1)
a
2
+ a
4
= 29 ? ar + ar
3
= 29
? ar(1 + r
2
) = 29
? a
2
r
2
(1 + r
2
)
2
= (29)
2
…(2)
By Eq. (1) & (2)
2
22
r 28
(1 r ) 29 29
?
??
?
2
r 28
1 r 29
?
?
? r 28 ?
? a
2
r
4
= 28 ? a
2
× (28)
2
= 28
?
1
a
28
?
? a
6
= ar
5
=
2
1
(28) 28 784
28
??
8. Let
? ? ?
??
1
x 1 y 2 z 3
L:
2 3 4
and
? ? ?
??
2
x 2 y 4 z 5
L:
3 4 5
be two lines. Then which
of the following points lies on the line of the
shortest distance between L
1
and L
2
?
(1)
??
??
??
??
5
, 7,1
3
(2)
??
??
??
1
2,3,
3
(3)
??
?
??
??
81
, 1,
33
(4)
??
?
??
??
14 22
, 3,
33
Ans. (4)
Sol.
P
Q
L
1
L
2
P(2 ? + 1, 3 ? + 2, 4 ? + 3) on L
1
Q(3µ + 2, 4µ + 4, 5µ + 5) on L
2
Dr’s of PQ = 3µ – 2 ? + 1, 4µ – 3? + 2, 5µ – 4 ? + 2
PQ ? L
1
3
? (3µ – 2? + 1)2 + (4µ – 3? + 2)3 + (5µ – 4? +
2)4 = 0
38µ – 29 ? + 16 = 0 …(1)
PQ ? L
2
? (3µ – 2? + 1)3 + (4µ – 3? + 2)4 + (5µ – 4? +
2)5 = 0
50µ – 38 ? + 21 = 0 …(2)
By (1) & (2)
1
3
?? ;
1
µ
6
?
?
??
5 13
P ,3,
33
??
??
??
&
3 10 25
Q , ,
2 3 6
??
??
??
Line PQ
5
x
3
1
6
?
y3
1
3
?
?
13
z
3
1
6
?
5 13
xz
y3
33
1 2 1
??
?
??
?
Point
14 22
, 3,
33
??
?
??
??
lies on the line PQ
9. The product of all solutions of the equation
? ? ?
?
2
e
5 log x 3 8
ex , x > 0, is :
(1) e
8/5
(2) e
6/5
(3) e
2
(4) e
Ans. (1)
Sol.
2
5( nx) 3 8
ex
?
?
??
2
5( nx) 3 8
ne n x
?
? ??
? 5( ?nx)
2
+ 3 = 8?nx
( ?nx = t)
? 5t
2
– 8t + 3 = 0
t
1
+ t
2
=
8
5
?nx
1
x
2
=
8
5
x
1
x
2
= e
8/5
10. If
?
? ? ? ?
?
?
n
r
r1
(2n 1)(2n 1)(2n 3)(2n 5)
T
64
, then
??
?
??
??
??
?
n
n
r1
r
1
lim
T
is equal to :
(1) 1 (2) 0
(3)
2
3
(4)
1
3
Ans. (3)
Sol. T
n
= S
n
– S
n–1
? T
n
=
1
8
(2n – 1)(2n + 1)(2n + 3)
??
n
18
T (2n 1)(2n 1)(2n 3)
?
? ? ?
??
?
nn
nn
r 1 r 1 r
11
lim lim8
T (2n 1)(2n 1)(2n 3)
? ? ? ?
??
?
? ? ?
??
??
?
n
8 1 1
lim
4 (2n 1)(2n 1) (2n 1)(2n 3)
??
??
??
??
? ? ? ?
??
?
?
?
n
1 1 1 1
lim 2 ...
1.3 3.5 3.5 5.7
??
?? ? ? ? ?
? ? ? ? ?
? ? ? ? ??
? ? ? ? ??
??
?
2
3
? ??
11. From all the English alphabets, five letters are
chosen and are arranged in alphabetical order. The
total number of ways, in which the middle letter is
‘M’, is :
(1) 14950 (2) 6084
(3) 4356 (4) 5148
Ans. (4)
Sol.
12 13
AB M N..........Z
12 13
22
Selection of two Selection of two
letters before M letters after M
C C 5148 ? ? ?
12. Let x = x(y) be the solution of the differential
equation
??
? ? ?
??
??
2
1
y dx x dy 0
y
. If x(1) = 1, then
??
??
??
1
x
2
is :
(1) ?
1
e
2
(2) ?
3
e
2
(3) 3 – e (4) 3 + e
Page 4
1
JEE–MAIN EXAMINATION – JANUARY 2025
MATHEMATICS TEST PAPER WITH SOLUTION
(HELD ON WEDNESDAY 22
nd
JANUARY 2025) TIME : 9:00 AM TO 12:00 NOON
SECTION-A
1. The number of non-empty equivalence relations on
the set {1,2,3} is :
(1) 6 (2) 7
(3) 5 (4) 4
Ans. (3)
Sol. Let R be the required relation
A = {(1, 1) (2, 2), (3, 3)}
(i) | R | = 3, when R = A
(ii) | R | = 5, e.g. R = A ? {(1, 2), (2, 1)}
Number of R can be [3]
(iii) R = {1, 2, 3} × {1, 2, 3}
Ans. (5)
2. Let ƒ : R ?R be a twice differentiable function
such that ƒ(x + y) = ƒ(x) ƒ(y) for all x, y ? R. If
ƒ'(0) = 4a and ƒ staisfies ƒ''(x) – 3a ƒ'(x) – ƒ(x) = 0,
a > 0, then the area of the region
R = {(x,y) | 0 ? y ? ƒ(ax), 0 ? x ? 2} is :
(1) e
2
– 1 (2) e
4
+ 1
(3) e
4
– 1 (4) e
2
+ 1
Ans. (1)
Sol. f(x + y) = f(x).f(y)
? f(x) = e
?x
f ?(0) = 4a
? f ?(x) = ?e
?x
? ? = 4a
So, f(x) = e
4ax
f ??(x) – 3af ?(x) – f (x) = 0
? ?
2
– 3a ? – 1 = 0
? 16a
2
– 12a
2
– 1 = 0 ? 4a
2
= 1 ? ?
1
a
2
?
x = 0
x = 2
f(ax) = e
x
F(x) = e
2x
2
x2
0
Area e dx e 1 ? ? ?
?
3. Let the triangle PQR be the image of the
triangle with vertices (1,3), (3,1) and (2, 4) in
the line x + 2y = 2. If the centroid of ?PQR is
the point ( ?, ?), then 15( ? – ?) is equal to :
(1) 24 (2) 19
(3) 21 (4) 22
Ans. (4)
Sol. Let ‘G’ be the centroid of ? formed by (1, 3) (3, 1)
& (2, 4)
8
G 2,
3
??
?
??
??
Image of G w.r.t. x + 2y – 2 = 0
16
8
22
2 3
3
2
1 2 1 4
??
??
?? ??
??
??
? ? ?
?
2 16
53
? ??
?
??
??
?
32 2
2
15 15
??
? ? ? ? ,
32 2 8 24
15 3 15
? ? ?
? ? ? ?
15( ? – ?) = – 2 + 24 = 22
4. Let z
1
, z
2
and z
3
be three complex numbers on the circle
|z| = 1 with
??
?
1
arg(z )
4
, arg(z
2
) = 0 and
?
?
3
arg(z )
4
.
If ? ? ? ? ? ?
2
1 2 2 3 3 1
z z z z z z 2 , ?, ? ? Z, then the
value of ?
2
+ ?
2
is :
(1) 24 (2) 41
(3) 31 (4) 29
Ans. (4)
Sol. Z
1
= e
–i ?/4
, Z
2
= 1, Z
3
= e
i ?/4
2
1 2 2 3 3 1
z z z z z z ?? =
2
i i i i
4 4 4 4
e 1 1 e e e
? ? ? ?
??
? ? ? ? ?
2
i i i
4 4 4
eee
? ? ?
??
??
2
i
4
2e i
?
?
?? =
2
2 2i i ? ? ?
=
? ? ? ?
22
2 1 2 ?? = 2 + 1 + 2 – 2 2 = 5 – 22
? = 5, ? = –2
? ?
2
+ ?
2
= 29
2
5. Using the principal values of the inverse
trigonometric functions the sum of the maximum
and the minimum values of 16((sec
–1
x)
2
+ (cosec
–1
x)
2
)
is :
(1) 24 ?
2
(2) 18 ?
2
(3) 31 ?
2
(4) 22 ?
2
Ans. (4)
Sol. 16(sec
–1
x)
2
+ (cosec
–1
x)
2
Sec
–1
x = a ?[0, ?] –
2
? ??
??
??
cosec
–1
x = a
2
?
?
=
2
2
22
16 a a 16 2a a
24
??
?? ?? ??
? ? ? ? ? ?
??
?? ??
??
????
??
max]
a =
?
= 16[2 ?
2
– ?
2
+
2
4
? ] = 20 ?
2
a
4
min]
?
?
=
2 2 2
2
2
16 2
16 4 4
?? ? ? ? ?
? ? ? ?
??
??
Sum = 22 ?
2
6. A coin is tossed three times. Let X denote the
number of times a tail follows a head. If ? and ?
2
denote the mean and variance of X, then the value
of 64( ? + ?
2
) is :
(1) 51 (2) 48
(3) 32 (4) 64
Ans. (2)
Sol. HHH ? 0
HHT ? 0
HTH ? 1
HTT ? 0
THH ? 1
THT ? 1
TTH ? 1
TTT ? 0
Probability distribution
i
i
x 0 1
11
P(x )
22
ii
1
xp
2
? ? ?
?
2 2 2
ii
x p µ ? ? ?
?
1 1 1
2 4 4
???
64(µ + ?
2
) =
11
64
24
??
?
??
??
= 48
7. Let a
1
, a
2
, a
3
..... be a G.P. of increasing positive
terms. If a
1
a
5
= 28 and a
2
+ a
4
= 29, the a
6
is equal to
(1) 628 (2) 526
(3) 784 (4) 812
Ans. (3)
Sol. a
1
.a
5
= 28 ? a.ar
4
= 28 ? a
2
r
4
= 28 …(1)
a
2
+ a
4
= 29 ? ar + ar
3
= 29
? ar(1 + r
2
) = 29
? a
2
r
2
(1 + r
2
)
2
= (29)
2
…(2)
By Eq. (1) & (2)
2
22
r 28
(1 r ) 29 29
?
??
?
2
r 28
1 r 29
?
?
? r 28 ?
? a
2
r
4
= 28 ? a
2
× (28)
2
= 28
?
1
a
28
?
? a
6
= ar
5
=
2
1
(28) 28 784
28
??
8. Let
? ? ?
??
1
x 1 y 2 z 3
L:
2 3 4
and
? ? ?
??
2
x 2 y 4 z 5
L:
3 4 5
be two lines. Then which
of the following points lies on the line of the
shortest distance between L
1
and L
2
?
(1)
??
??
??
??
5
, 7,1
3
(2)
??
??
??
1
2,3,
3
(3)
??
?
??
??
81
, 1,
33
(4)
??
?
??
??
14 22
, 3,
33
Ans. (4)
Sol.
P
Q
L
1
L
2
P(2 ? + 1, 3 ? + 2, 4 ? + 3) on L
1
Q(3µ + 2, 4µ + 4, 5µ + 5) on L
2
Dr’s of PQ = 3µ – 2 ? + 1, 4µ – 3? + 2, 5µ – 4 ? + 2
PQ ? L
1
3
? (3µ – 2? + 1)2 + (4µ – 3? + 2)3 + (5µ – 4? +
2)4 = 0
38µ – 29 ? + 16 = 0 …(1)
PQ ? L
2
? (3µ – 2? + 1)3 + (4µ – 3? + 2)4 + (5µ – 4? +
2)5 = 0
50µ – 38 ? + 21 = 0 …(2)
By (1) & (2)
1
3
?? ;
1
µ
6
?
?
??
5 13
P ,3,
33
??
??
??
&
3 10 25
Q , ,
2 3 6
??
??
??
Line PQ
5
x
3
1
6
?
y3
1
3
?
?
13
z
3
1
6
?
5 13
xz
y3
33
1 2 1
??
?
??
?
Point
14 22
, 3,
33
??
?
??
??
lies on the line PQ
9. The product of all solutions of the equation
? ? ?
?
2
e
5 log x 3 8
ex , x > 0, is :
(1) e
8/5
(2) e
6/5
(3) e
2
(4) e
Ans. (1)
Sol.
2
5( nx) 3 8
ex
?
?
??
2
5( nx) 3 8
ne n x
?
? ??
? 5( ?nx)
2
+ 3 = 8?nx
( ?nx = t)
? 5t
2
– 8t + 3 = 0
t
1
+ t
2
=
8
5
?nx
1
x
2
=
8
5
x
1
x
2
= e
8/5
10. If
?
? ? ? ?
?
?
n
r
r1
(2n 1)(2n 1)(2n 3)(2n 5)
T
64
, then
??
?
??
??
??
?
n
n
r1
r
1
lim
T
is equal to :
(1) 1 (2) 0
(3)
2
3
(4)
1
3
Ans. (3)
Sol. T
n
= S
n
– S
n–1
? T
n
=
1
8
(2n – 1)(2n + 1)(2n + 3)
??
n
18
T (2n 1)(2n 1)(2n 3)
?
? ? ?
??
?
nn
nn
r 1 r 1 r
11
lim lim8
T (2n 1)(2n 1)(2n 3)
? ? ? ?
??
?
? ? ?
??
??
?
n
8 1 1
lim
4 (2n 1)(2n 1) (2n 1)(2n 3)
??
??
??
??
? ? ? ?
??
?
?
?
n
1 1 1 1
lim 2 ...
1.3 3.5 3.5 5.7
??
?? ? ? ? ?
? ? ? ? ?
? ? ? ? ??
? ? ? ? ??
??
?
2
3
? ??
11. From all the English alphabets, five letters are
chosen and are arranged in alphabetical order. The
total number of ways, in which the middle letter is
‘M’, is :
(1) 14950 (2) 6084
(3) 4356 (4) 5148
Ans. (4)
Sol.
12 13
AB M N..........Z
12 13
22
Selection of two Selection of two
letters before M letters after M
C C 5148 ? ? ?
12. Let x = x(y) be the solution of the differential
equation
??
? ? ?
??
??
2
1
y dx x dy 0
y
. If x(1) = 1, then
??
??
??
1
x
2
is :
(1) ?
1
e
2
(2) ?
3
e
2
(3) 3 – e (4) 3 + e
4
Ans. (3)
Sol.
23
dx 1 1
x
dy y y
??
??
??
??
I.F. =
2
1 1
dy
yy
ee
?
?
?
1
1
y
t
3
1
x.e e . dy
y
?
? ??
??
??
??
?
Put
1
t
y
??
2
1
dy dt
y
??
1
t y
x.e t.e dt
?
??
?
1
tt y
x.e te e C
?
? ? ? ?
1 1 1
y y y
1
x.e e e C
y
? ? ?
?
? ? ?
x = 1, y = 1
1 1 1
C
e e e
? ? ?
?
1
C
e
??
Put y =
1
2
2 2 2
x 2 1 1
e e e e
? ? ?
x = 3 – e
13. Let the parabola y = x
2
+ px – 3, meet the
coordinate axes at the points P, Q and R. If the
circle C with centre at (–1, –1) passes through the
points P, Q and R, then the area of ?PQR is :
(1) 4 (2) 6
(3) 7 (4) 5
Ans. (2)
Sol. y = x
2
+ px – 3
Let P( ?, 0), Q( ?, 0), R(0, –3)
Circle with centre (–1, –1) is (x + 1)
2
+ (y + 1)
2
= r
2
Passes through (0, –3)
1
2
+ (–2)
2
= r
2
]
r
2
= 5
(x + 1)
2
+ (y + 1)
2
= 5
Put y = 0
(x + 1)
2
= 5 – 1
(x + 1)
2
= 4
x + 1 = ±2
x = 1 or x = –3
? P(1, 0) and Q(–3,0)
Area of ?PQR =
1 0 1
1
3 0 1 6
2
0 3 1
??
?
14. A circle C of radius 2 lies in the second quadrant and
touches both the coordinate axes. Let r be the radius
of a circle that has centre at the point (2, 5) and
intersects the circle C at exactly two points. If the set
of all possible values of r is the interval ( ?, ?), then
3 ? – 2 ? is equal to :
(1) 15 (2) 14
(3) 12 (4) 10
Ans. (1)
Sol.
(–2,2)
S
1
: (x + 2)
2
+ (y – 2)
2
= 2
2
S
2
: (x – 2)
2
+ (y – 5)
2
= r
2
Both circle intersect at two points
? |r
1
– r
2
| < c
1
c
2
< r
1
+ r
2
|r – 2| < 5 < 2 + r
? 3 < r < 7
r ? (3, 7)
? = 3, ? = 7
3 ? – 2? = 15
15. Let for ƒ(x) = 7tan
8
x + 7tan
6
x – 3tan
4
x – 3tan
2
x,
?
?
?
/4
1
0
I ƒ(x)dx and
?
?
?
/4
2
0
I xƒ(x)dx . Then 7I
1
+ 12I
2
is equal to :
(1) 2? (2) ?
(3) 1 (4) 2
Ans. (3)
Page 5
1
JEE–MAIN EXAMINATION – JANUARY 2025
MATHEMATICS TEST PAPER WITH SOLUTION
(HELD ON WEDNESDAY 22
nd
JANUARY 2025) TIME : 9:00 AM TO 12:00 NOON
SECTION-A
1. The number of non-empty equivalence relations on
the set {1,2,3} is :
(1) 6 (2) 7
(3) 5 (4) 4
Ans. (3)
Sol. Let R be the required relation
A = {(1, 1) (2, 2), (3, 3)}
(i) | R | = 3, when R = A
(ii) | R | = 5, e.g. R = A ? {(1, 2), (2, 1)}
Number of R can be [3]
(iii) R = {1, 2, 3} × {1, 2, 3}
Ans. (5)
2. Let ƒ : R ?R be a twice differentiable function
such that ƒ(x + y) = ƒ(x) ƒ(y) for all x, y ? R. If
ƒ'(0) = 4a and ƒ staisfies ƒ''(x) – 3a ƒ'(x) – ƒ(x) = 0,
a > 0, then the area of the region
R = {(x,y) | 0 ? y ? ƒ(ax), 0 ? x ? 2} is :
(1) e
2
– 1 (2) e
4
+ 1
(3) e
4
– 1 (4) e
2
+ 1
Ans. (1)
Sol. f(x + y) = f(x).f(y)
? f(x) = e
?x
f ?(0) = 4a
? f ?(x) = ?e
?x
? ? = 4a
So, f(x) = e
4ax
f ??(x) – 3af ?(x) – f (x) = 0
? ?
2
– 3a ? – 1 = 0
? 16a
2
– 12a
2
– 1 = 0 ? 4a
2
= 1 ? ?
1
a
2
?
x = 0
x = 2
f(ax) = e
x
F(x) = e
2x
2
x2
0
Area e dx e 1 ? ? ?
?
3. Let the triangle PQR be the image of the
triangle with vertices (1,3), (3,1) and (2, 4) in
the line x + 2y = 2. If the centroid of ?PQR is
the point ( ?, ?), then 15( ? – ?) is equal to :
(1) 24 (2) 19
(3) 21 (4) 22
Ans. (4)
Sol. Let ‘G’ be the centroid of ? formed by (1, 3) (3, 1)
& (2, 4)
8
G 2,
3
??
?
??
??
Image of G w.r.t. x + 2y – 2 = 0
16
8
22
2 3
3
2
1 2 1 4
??
??
?? ??
??
??
? ? ?
?
2 16
53
? ??
?
??
??
?
32 2
2
15 15
??
? ? ? ? ,
32 2 8 24
15 3 15
? ? ?
? ? ? ?
15( ? – ?) = – 2 + 24 = 22
4. Let z
1
, z
2
and z
3
be three complex numbers on the circle
|z| = 1 with
??
?
1
arg(z )
4
, arg(z
2
) = 0 and
?
?
3
arg(z )
4
.
If ? ? ? ? ? ?
2
1 2 2 3 3 1
z z z z z z 2 , ?, ? ? Z, then the
value of ?
2
+ ?
2
is :
(1) 24 (2) 41
(3) 31 (4) 29
Ans. (4)
Sol. Z
1
= e
–i ?/4
, Z
2
= 1, Z
3
= e
i ?/4
2
1 2 2 3 3 1
z z z z z z ?? =
2
i i i i
4 4 4 4
e 1 1 e e e
? ? ? ?
??
? ? ? ? ?
2
i i i
4 4 4
eee
? ? ?
??
??
2
i
4
2e i
?
?
?? =
2
2 2i i ? ? ?
=
? ? ? ?
22
2 1 2 ?? = 2 + 1 + 2 – 2 2 = 5 – 22
? = 5, ? = –2
? ?
2
+ ?
2
= 29
2
5. Using the principal values of the inverse
trigonometric functions the sum of the maximum
and the minimum values of 16((sec
–1
x)
2
+ (cosec
–1
x)
2
)
is :
(1) 24 ?
2
(2) 18 ?
2
(3) 31 ?
2
(4) 22 ?
2
Ans. (4)
Sol. 16(sec
–1
x)
2
+ (cosec
–1
x)
2
Sec
–1
x = a ?[0, ?] –
2
? ??
??
??
cosec
–1
x = a
2
?
?
=
2
2
22
16 a a 16 2a a
24
??
?? ?? ??
? ? ? ? ? ?
??
?? ??
??
????
??
max]
a =
?
= 16[2 ?
2
– ?
2
+
2
4
? ] = 20 ?
2
a
4
min]
?
?
=
2 2 2
2
2
16 2
16 4 4
?? ? ? ? ?
? ? ? ?
??
??
Sum = 22 ?
2
6. A coin is tossed three times. Let X denote the
number of times a tail follows a head. If ? and ?
2
denote the mean and variance of X, then the value
of 64( ? + ?
2
) is :
(1) 51 (2) 48
(3) 32 (4) 64
Ans. (2)
Sol. HHH ? 0
HHT ? 0
HTH ? 1
HTT ? 0
THH ? 1
THT ? 1
TTH ? 1
TTT ? 0
Probability distribution
i
i
x 0 1
11
P(x )
22
ii
1
xp
2
? ? ?
?
2 2 2
ii
x p µ ? ? ?
?
1 1 1
2 4 4
???
64(µ + ?
2
) =
11
64
24
??
?
??
??
= 48
7. Let a
1
, a
2
, a
3
..... be a G.P. of increasing positive
terms. If a
1
a
5
= 28 and a
2
+ a
4
= 29, the a
6
is equal to
(1) 628 (2) 526
(3) 784 (4) 812
Ans. (3)
Sol. a
1
.a
5
= 28 ? a.ar
4
= 28 ? a
2
r
4
= 28 …(1)
a
2
+ a
4
= 29 ? ar + ar
3
= 29
? ar(1 + r
2
) = 29
? a
2
r
2
(1 + r
2
)
2
= (29)
2
…(2)
By Eq. (1) & (2)
2
22
r 28
(1 r ) 29 29
?
??
?
2
r 28
1 r 29
?
?
? r 28 ?
? a
2
r
4
= 28 ? a
2
× (28)
2
= 28
?
1
a
28
?
? a
6
= ar
5
=
2
1
(28) 28 784
28
??
8. Let
? ? ?
??
1
x 1 y 2 z 3
L:
2 3 4
and
? ? ?
??
2
x 2 y 4 z 5
L:
3 4 5
be two lines. Then which
of the following points lies on the line of the
shortest distance between L
1
and L
2
?
(1)
??
??
??
??
5
, 7,1
3
(2)
??
??
??
1
2,3,
3
(3)
??
?
??
??
81
, 1,
33
(4)
??
?
??
??
14 22
, 3,
33
Ans. (4)
Sol.
P
Q
L
1
L
2
P(2 ? + 1, 3 ? + 2, 4 ? + 3) on L
1
Q(3µ + 2, 4µ + 4, 5µ + 5) on L
2
Dr’s of PQ = 3µ – 2 ? + 1, 4µ – 3? + 2, 5µ – 4 ? + 2
PQ ? L
1
3
? (3µ – 2? + 1)2 + (4µ – 3? + 2)3 + (5µ – 4? +
2)4 = 0
38µ – 29 ? + 16 = 0 …(1)
PQ ? L
2
? (3µ – 2? + 1)3 + (4µ – 3? + 2)4 + (5µ – 4? +
2)5 = 0
50µ – 38 ? + 21 = 0 …(2)
By (1) & (2)
1
3
?? ;
1
µ
6
?
?
??
5 13
P ,3,
33
??
??
??
&
3 10 25
Q , ,
2 3 6
??
??
??
Line PQ
5
x
3
1
6
?
y3
1
3
?
?
13
z
3
1
6
?
5 13
xz
y3
33
1 2 1
??
?
??
?
Point
14 22
, 3,
33
??
?
??
??
lies on the line PQ
9. The product of all solutions of the equation
? ? ?
?
2
e
5 log x 3 8
ex , x > 0, is :
(1) e
8/5
(2) e
6/5
(3) e
2
(4) e
Ans. (1)
Sol.
2
5( nx) 3 8
ex
?
?
??
2
5( nx) 3 8
ne n x
?
? ??
? 5( ?nx)
2
+ 3 = 8?nx
( ?nx = t)
? 5t
2
– 8t + 3 = 0
t
1
+ t
2
=
8
5
?nx
1
x
2
=
8
5
x
1
x
2
= e
8/5
10. If
?
? ? ? ?
?
?
n
r
r1
(2n 1)(2n 1)(2n 3)(2n 5)
T
64
, then
??
?
??
??
??
?
n
n
r1
r
1
lim
T
is equal to :
(1) 1 (2) 0
(3)
2
3
(4)
1
3
Ans. (3)
Sol. T
n
= S
n
– S
n–1
? T
n
=
1
8
(2n – 1)(2n + 1)(2n + 3)
??
n
18
T (2n 1)(2n 1)(2n 3)
?
? ? ?
??
?
nn
nn
r 1 r 1 r
11
lim lim8
T (2n 1)(2n 1)(2n 3)
? ? ? ?
??
?
? ? ?
??
??
?
n
8 1 1
lim
4 (2n 1)(2n 1) (2n 1)(2n 3)
??
??
??
??
? ? ? ?
??
?
?
?
n
1 1 1 1
lim 2 ...
1.3 3.5 3.5 5.7
??
?? ? ? ? ?
? ? ? ? ?
? ? ? ? ??
? ? ? ? ??
??
?
2
3
? ??
11. From all the English alphabets, five letters are
chosen and are arranged in alphabetical order. The
total number of ways, in which the middle letter is
‘M’, is :
(1) 14950 (2) 6084
(3) 4356 (4) 5148
Ans. (4)
Sol.
12 13
AB M N..........Z
12 13
22
Selection of two Selection of two
letters before M letters after M
C C 5148 ? ? ?
12. Let x = x(y) be the solution of the differential
equation
??
? ? ?
??
??
2
1
y dx x dy 0
y
. If x(1) = 1, then
??
??
??
1
x
2
is :
(1) ?
1
e
2
(2) ?
3
e
2
(3) 3 – e (4) 3 + e
4
Ans. (3)
Sol.
23
dx 1 1
x
dy y y
??
??
??
??
I.F. =
2
1 1
dy
yy
ee
?
?
?
1
1
y
t
3
1
x.e e . dy
y
?
? ??
??
??
??
?
Put
1
t
y
??
2
1
dy dt
y
??
1
t y
x.e t.e dt
?
??
?
1
tt y
x.e te e C
?
? ? ? ?
1 1 1
y y y
1
x.e e e C
y
? ? ?
?
? ? ?
x = 1, y = 1
1 1 1
C
e e e
? ? ?
?
1
C
e
??
Put y =
1
2
2 2 2
x 2 1 1
e e e e
? ? ?
x = 3 – e
13. Let the parabola y = x
2
+ px – 3, meet the
coordinate axes at the points P, Q and R. If the
circle C with centre at (–1, –1) passes through the
points P, Q and R, then the area of ?PQR is :
(1) 4 (2) 6
(3) 7 (4) 5
Ans. (2)
Sol. y = x
2
+ px – 3
Let P( ?, 0), Q( ?, 0), R(0, –3)
Circle with centre (–1, –1) is (x + 1)
2
+ (y + 1)
2
= r
2
Passes through (0, –3)
1
2
+ (–2)
2
= r
2
]
r
2
= 5
(x + 1)
2
+ (y + 1)
2
= 5
Put y = 0
(x + 1)
2
= 5 – 1
(x + 1)
2
= 4
x + 1 = ±2
x = 1 or x = –3
? P(1, 0) and Q(–3,0)
Area of ?PQR =
1 0 1
1
3 0 1 6
2
0 3 1
??
?
14. A circle C of radius 2 lies in the second quadrant and
touches both the coordinate axes. Let r be the radius
of a circle that has centre at the point (2, 5) and
intersects the circle C at exactly two points. If the set
of all possible values of r is the interval ( ?, ?), then
3 ? – 2 ? is equal to :
(1) 15 (2) 14
(3) 12 (4) 10
Ans. (1)
Sol.
(–2,2)
S
1
: (x + 2)
2
+ (y – 2)
2
= 2
2
S
2
: (x – 2)
2
+ (y – 5)
2
= r
2
Both circle intersect at two points
? |r
1
– r
2
| < c
1
c
2
< r
1
+ r
2
|r – 2| < 5 < 2 + r
? 3 < r < 7
r ? (3, 7)
? = 3, ? = 7
3 ? – 2? = 15
15. Let for ƒ(x) = 7tan
8
x + 7tan
6
x – 3tan
4
x – 3tan
2
x,
?
?
?
/4
1
0
I ƒ(x)dx and
?
?
?
/4
2
0
I xƒ(x)dx . Then 7I
1
+ 12I
2
is equal to :
(1) 2? (2) ?
(3) 1 (4) 2
Ans. (3)
5
Sol. f(x) = (7tan
6
x – 3tan
2
x)(sec
2
x)
/4
6 2 2
1
0
I (7 tan x 3tan x)(sec x)dx
?
??
?
Put tanx = t
1
1
6 2 7 3
1
0
0
I (7t 3t )dt t t 0 ?? ? ? ? ? ?
?? ?
/4
6 2 2
2
I
0
II
I x (7 tan x 3tan x)(sec x)dx
?
??
?
? ?
/4
/4
7 3 7 3
0
0
x tan x tan x (tan x tan x)dx
?
?
??
? ? ? ?
??
?
? ? ? ?
/4
3 2 2
0
0 tan x tan x 1 1 tan x dx
?
? ? ? ?
?
Put tanx = t
? ?
1 64
53
0
t t 1
t t dt
6 4 12
??
? ? ? ? ? ? ?
??
??
?
7I
1
+ 12I
2
= 1
16. Let ƒ(x) be a real differentiable function such that
ƒ(0) = 1 and ƒ(x + y) = ƒ(x)ƒ'(y) + ƒ'(x) ƒ(y) for all
x, y ? R. Then
?
?
100
e
n1
log ƒ(n) is equal to :
(1) 2384 (2) 2525
(3) 5220 (4) 2406
Ans. (2)
Sol. f(x + y) = f(x) f ?(y) + f ?(x) f(x)
Put = x = y = 0
f(0) = f(0)f ?(0) + f ?(0)f(0)
f ?(0) =
1
2
Put y = 0
f(x) = f(x) f ?(0) + f ?(x)f(0)
? ? ? ? ? ?
1
f x f x f x
2
? ? ?
? ?
? ? fx
fx
2
??
dy y dy dx
dx 2 y 2
? ? ?
??
? ?ny =
x
c
2
?
? f (0) = 1 ? C = 0
?ny =
2
?
? f(x) =
x/2
e
?n f (n) =
n
2
? ?
100 100
n 1 n 1
1 5050
f n n
22
??
??
??
= 2525
17. Let A = {1,2,3,.......,10} and
??
??
??
??
m
B : m, n A, m < n and gcd (m, n) =1
n
.
Then n(B) is equal to :
(1) 31 (2) 36
(3) 37 (4) 29
Ans. (1)
Sol. A = {1, 2, ….10}
B {
m
n
= m, n ??A, m < n, gcd (m, n) = 1}
n(B)
n = 2
1
2
??
??
??
n = 3
12
,
33
??
??
??
n = 4
13
,
44
??
??
??
n = 5
1 2 3 4
, , ,
5555
??
??
??
n = 6
15
,
66
??
??
??
n = 7
1 2 3 4 5 6
,,,,,
777777
??
??
??
n = 8
1 3 5 7
, , ,
8 8 8 8
??
??
??
n = 9
1 2 4 5 7 8
, , , , ,
9 9 9 9 9 9
??
??
??
n = 10
1 3 7 9
,,,
10 10 10 10
??
??
??
n(B) = 31
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