FINAL JEE–MAIN EXAMINATION – JANUARY, 2024
(Held On Thursday 01st February, 2024) TIME : 9 : 00 AM to 12 : 00 NOON
MATHEMATICS TEST PAPER WITH SOLUTION
SECTION-A
4
xdx
1. A bag contains 8 balls, whose colours are either Sol. sin 4
(2 x) cos 4 (2 x)
white or black. 4 balls are drawn at random 0
without replacement and it was found that 2 balls 1
Let 2x t then dx dt
are white and other 2 balls are black. The 2
probability that the bag contains equal number of
12 tdt
white and black balls is: I 4
4 0 sin t cos 4 t
2 2
(1) (2)
5 7 2 t dt
1
I 2
(3)
1
(4)
1 40
7 5 sin 4 t cos 4 t
2 2
Ans. (2)
2 dt
Sol. 1
4 0 sin 4 t cos 4 t
I 2 I
P(4W4B/2W2B) =
P(4W 4 B) P(2W 2 B / 4W 4 B)
P(2W 6 B) P(2W 2 B / 2W 6 B) P(3W 5 B) P(2W 2 B / 3W 5 B) 2
dt
8 sin
............. P(6W 2 B) P(2W 2 B / 6W 2 B) 2I
0
4
t cos 4 t
1 4 C2 4C2
8
5 C4 2
sec 4 tdt
8 0 tan 4 t 1
= 2I
1 C2 C2 1 C2 5C2
2 6 3
1 6 C 2C2
8 8 ... 28
5 C4 5 C4 5 C4 Let tant = y then sec2t dt = dy
(1 y 2 )dy
=
2 2I
8 1 y4
7 0
1
1
y2
2. The value of the integral dy
16 0 y 2 1
4
xdx y2
sin 4
(2 x) cos 4 (2 x)
equals :
1
0 Put y p
y
2 2 2 2
(1) (2) dp
8 16 I
2
16 p2 2
2 2
2 2
(3) (4)
32 64 1 p
tan
Ans. (3) 16 2 2
2
I
16 2
, 2 1 Sol.
1 0
3. If A = , B = , C = ABAT and X Finding tan (A + B) we get
1 2 1 1 tan (A + B) =
= ATC2A, then det X is equal to : 1 x
(1) 243 tan A tan B x( x x 1)
2
x x 1
2
(2) 729 1 tan A tan B 1
1
x x 1
2
(3) 27
(4) 891
tan (A + B) =
1 x x2 x 1
Ans. (2) x 2
x x
1 x
Sol.
x2 x 1
2 1
A det( A) 3 x 2
x x
1 2
1 0 x2 x 1
tan( A B) tan C
B det( B) 1 x x
1 1
A B C
Now C = ABAT det(C) = (dct (A))2 x det(B)
C 9 5. If n is the number of ways five different employees
can sit into four indistinguishable offices where
Now |X| = |ATC2A| any office may have any number of persons
= |AT| |C|2 |A| including zero, then n is equal to:
= |A|2 |C|2 (1) 47
(2) 53
= 9 x 81
(3) 51
= 729 (4) 43
1 x Ans. (3)
4. If tanA = , tan B Sol.
x( x 2 x 1) x2 x 1
Total ways to partition 5 into 4 parts are :
and 5, 0, 0, 0 1 way
5!
1
4, 1, 0, 0 5 ways
tan C x x x3 2 1 2
, 0 A, B, C
2
, then 4!
5!
3, 2, 0, 0, 10 ways
A + B is equal to : 3!2!
(1) C 5!
2, 2,0,1 15 ways
(2) C 2!2!2!
5!
(3) 2 C 2,1,1,1 10 ways
2!(1!)3 3!
(4) C 5!
2 3,1,1,0 10 ways
3!2!
Ans. (1) Total 1+5+10+15+10+10 = 51 ways
, 6. LetS={ z C : z 1 1 and Sol. Median = 170 125, a, b, 170, 190, 210, 230
Mean deviation about
2 1 z z i z z 2 2 }. Let z1, z2
Median =
S be such that z1 max z and z2 min z . 0 45 60 20 40 170 a 170 b 205
zs zs
2 7 7
Then 2z1 z2 equals :
a + b = 300
(1) 1 (2) 4
(3) 3 (4) 2 Mean = 170 125 230 190 210 a b 175
7
Ans. (4)
Mean deviation
Sol. Let Z = x + iy
Then (x - 1)2 + y2 = 1 (1) About mean =
( 2 1) x y 2 (2)
8. Let a 5iˆ ˆj 3kˆ, b iˆ 2 ˆj 4kˆ and
Solving (1) & (2) we get
Either x = 1 or x
1
(3)
c a b iˆ iˆ iˆ. Then c iˆ ˆj kˆ is
2 2
equal to
On solving (3) with (2) we get
For x = 1 y = 1 Z2 = 1 + i
& for (1) –12 (2) –10
1 1 1 i (3) –13 (4) –15
x y 2 Z1 1
2 2 2 2 2 Ans. (1)
Now
2
Sol. a 5iˆ j 3kˆ
2 z1 z2
b iˆ 2 ˆj 4kˆ
2
1
1 2 i (1 i)
2
(a b ) iˆ a iˆ b b iˆ a
2 5b a
2
2 5b a iˆ iˆ
7. Let the median and the mean deviation about the
median of 7 observation 170, 125, 230, 190, 210, a, b 11 ˆj 23kˆ iˆ iˆ
205
be 170 and respectively. Then the mean
7
11kˆ 23 ˆj iˆ
deviation about the mean of these 7 observations is :
(1) 31
(2) 28
11 ˆj 23kˆ
(3) 30 c . iˆ ˆj kˆ 11 23 12
(4) 32
Ans. (3)
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller clover1. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $2.99. You're not tied to anything after your purchase.