Official Quant thread for CAT 2013

MBA CAT 2022
2721
@Messy_19 said:
Thoda explanation possible in detail? nahi samja concept behind this..@sujamait
ek number le lo
12345689 ismein 7 missing hai...

isi number ka 9 se remainder le lo jo ki 2 aa rha hai...
so missing number is nothing but 9-2 = 7 ..yehi funda hai yar.
2722
@sumeet1489 said:
ye to direct ho jayega 1)42*8-92)21*49-363)20*10-1254)50*16-1option 3
42*18 - 9 ?? :P
2723
@soumitrabengeri said:
One hundred identical coins each with prob P of showing up heads are tossed once. If 01) 1/212) 49/1013) 50/1014) 51/101P.S @sujamait ..hope this helps
P(h) = P
P(t) = 1-P

P(h in 50 coins) = (P^50)*(1-P)^50 * [100!/50!50!]
P(h in 51 coins) = (P^51)*(1-P)^49 * [100!/51!49!]

Equating both, => (1-P)/50 = P/51
=> 51- 51P = 50P
=> P = 51/101 ?
2724
@soumitrabengeri said:
Option c
@sumeet1489 said:
ye to direct ho jayega 1)42*8-92)21*49-363)20*10-1254)50*16-1option 3
@sujamait said:
3 lag rha hai..soumitrabengeriaapke Q mein kuch typo hai ?
Ans given is : option 1
Edit: I think answer given is wrong.. Option 3 is definitely correct.. 😃
2725
@Messy_19 said:
The total number of relations that can be defined from a Set A to set B is 4096. If m and n are the number of elements in set A and set B respectively, find the total number of values the ordered pair (m,n) can take?43689
I guess,
n^m = 4096
n=4096,m=1
n=2,m=12
n=4,m=6
n=8,m=4
n=16,m=3
n=64,m=2

So,6 hai kya ?
2726
@ScareCrow28 said:
Ans given is : option 1
bhai yeh
30^2 €“10^2 - 5^3

5^3 hee hai ya 5^2 ??
2727
@rkshtsurana said:
2^29 is a 9 digit number containing all distinct digits. Which number is missing ?
remainder by 9

E(9) = 6

2^29 mod 9 = R
2*R mod 9 = 1

=> R = 5

so number missing = 9 - 5 = 4
2728
@ScareCrow28 bhavnao ko samajh gaye na matlab ;)
question ka source kya hai vaise
2729
@ScareCrow28 said:
Ans given is : option 1
1 ka value comes out to be 747..whereas 3 ka value is 675..the answer given should be wrong
2730
@Messy_19 said:
The total number of relations that can be defined from a Set A to set B is 4096. If m and n are the number of elements in set A and set B respectively, find the total number of values the ordered pair (m,n) can take?43689
n^m = 4096 = 2^12

n,m are positive integers => n = power of 2 = 2^a (a is a factor of 12)
m = factor of 12

a = 1 => (2,12)
a = 2 => (4,6)
a = 3 => (8,4)
a = 4 => (16,3)
a = 6 => (64,2)
a = 12 => (4096,1)

6 values ?
2731
@sumeet1489 said:
@ScareCrow28 bhavnao ko samajh gaye na matlab question ka source kya hai vaise
XAT mock by princeton :P
2732
@ScareCrow28 are ye XAT mock hai ya XAT mockery :P
aisa question XAT mein aa bhi gaya to power 2 ya 3 nahi hogi ;)
2733
@soumitrabengeri said:
One hundred identical coins each with prob P of showing up heads are tossed once. If 01) 1/212) 49/1013) 50/1014) 51/101P.S @sujamait ..hope this helps
for 50 heads
probability = C(100, 50)*(P)^50 * (1 - P)^50

for 51 heads,
probability = C(100, 51)* (P)^51 * (1 - P)^49

by equating them we will get
(1 - P)/50 = P/51
P = 51/101
2734
@ScareCrow28 said:
XAT mock by princeton
hehe...sahi hai..XAT ko CAT samajh rakha hai inhone...XAT cat ke papa ban chuke hein ab..


The function
f(
n) is defined on the set of integers.
f(
n) satisfies the given conditions;
f(n) = n €“ 3 if n ‰Ľ 1000

= f(f(n + 5)) if n
Find f(84).
OPTIONS

1) 100
2) 84
3) 998
4) 997



2735
a, b and c are the sides of a triangle. Equations ax^2 + bx + c = 0 and 3x^2 + 4x + 5 = 0 have a common root. Then angle C is equal to
(1) 600 (2) 900 (3) 1200 (4) None of these
2736

6 is correct.


Nasik express travels to and fro between Nasik and Kanpur. The express halts at 10 other stations in its route. Find the number of types of tickets required so that it is possible to book a passenger from every station to every other station.

12!/2!

12!/(10!*2!)

12!/10!

12!/(2!) ˛(10!)

None
2737
@ScareCrow28 said:
a, b and c are the sides of a triangle. Equations ax^2 + bx + c = 0 and 3x^2 + 4x + 5 = 0 have a common root. Then angle C is equal to(1) 600 (2) 900 (3) 1200 (4) None of these
90?

2738
@sujamait said:
hehe...sahi hai..XAT ko CAT samajh rakha hai inhone...XAT cat ke papa ban chuke hein ab..The functionf(n) is defined on the set of integers.f(n) satisfies the given conditions;f(n) = n €“ 3 if n ‰Ľ 1000= f(f(n + 5)) if n Find f(84).OPTIONS1) 100 2) 84 3) 998 4) 997
is it 3????
2739
@ScareCrow28 said:
a, b and c are the sides of a triangle. Equations ax^2 + bx + c = 0 and 3x^2 + 4x + 5 = 0 have a common root. Then angle C is equal to(1) 600 (2) 900 (3) 1200 (4) None of these
Both roots of the equation 3x^2 + 4x + 5 are complex, so both roots will be common, means a = 3k, b = 4k and c = 5k

CosC = (a² + b² - c²)/(2ab) = 0

C = 90°
Option 2
2740
@sujamait said:
hehe...sahi hai..XAT ko CAT samajh rakha hai inhone...XAT cat ke papa ban chuke hein ab..

The function
f(
n) is defined on the set of integers.
f(
n) satisfies the given conditions;
f
(
n
) =
n
€“ 3 if
n
‰Ľ 1000

=
f
(
f
(
n
+ 5)) if
n

Find
f
(84).
OPTIONS

1) 100
2) 84
3) 998
4) 997


997 you had posted this question just few days back 😁