Official Quant thread for CAT 2013

MBA CAT 2024
23247
@sameersapre23 said:
Ten people A, B, C, D, E, F, G, H, I and J attend a conference. F wants to speak before A, B wants to speak after A, C wants to speak after B and D wants to speak after C. In how many distinct orders can the 10 people speak?10!10c55! 10c5NONE OF THESE
The 5 people can be arranged in only 1 way out of 5!. Hence 10!/5! = 5! * 10C5.

regards
scrabbler
23248
Two dice are thrown simultaneously. The probability of getting a multiple of 2 on one dice and a multiple of 3 on other is:

A. ⅙ B. ⅓ C. 5/12 D. 11/36

23249
Two dice are thrown simultaneously. The probability of getting a multiple of 2 on one dice and a multiple of 3 on other is:

A. 1/6 B. 1/3 C. 5/12 D. 11/36 (No OA :mg:)
ďťż
23250
Out of 21 tickets marked with numbers from 1 to 21, three are drawn at random. Find the probability that these three numbers are in A.P.

100/21C3
99/21C3
101/21C3
none of these
23251
@sameersapre23 said:
Three men toss a coin in succession for a prize to be given to the person who first obtains a head. What is third man chance of winning the prize?1/87/81/71/2
Ratio of Probability will be 4 : 2 : 1 => 1/ ( 4+2+1) = 1/7.
23252
@sameersapre23 said:
Aryan and Nandini are siblings. They participated in two different competition i.e. swimming and wrestling respectively. Aryan participated in swimming and Nandini in wrestling. Both were awarded rank between 1 to 50 (including 1 and 50). What is the probability that difference between their ranks is not more than 10 rank?9 / 2517 / 4040 / 1003 / 10
9/25? Tried graphically....

regards
scrabbler
23253
@sameersapre23 said:
21 straught lines. no 2 of which are parallel. no 3 of which are concurrent are drawn on a plane. into how many regions is the plane divided by the lines?4412301024264232
232.

Summation(n)+1

regards
scrabbler
23254
@sameersapre23 said:
How many different terms does the product (a + b + c+ d + e + f)(c + d + e + f + g) have?1130252429
24 only
23255

i dont have OA of any of the questions , these all are from the mock i have....!! With no answers.

We will dicuss them......!!
23256
@sameersapre23 said:
Three men toss a coin in succession for a prize to be given to the person who first obtains a head. What is third man chance of winning the prize?1/87/81/71/2
1/7
23257
@YouMadFellow said:
Two dice are thrown simultaneously. The probability of getting a multiple of 2 on one dice and a multiple of 3 on other is: A. 1/6 B. 1/3 C. 5/12 D. 11/36 (No OA )
11/36 (No method )

regards
scrabbler
23258
@sameersapre23 said:
Out of 21 tickets marked with numbers from 1 to 21, three are drawn at random. Find the probability that these three numbers are in A.P.100/21C399/21C3101/21C3none of these
Sample Space = 21 C 3.

Now, APs with 1 as first term will be = [ 21 - 1]/2 = 10.
With 2 as the first term will be = 9.
With 3 as first term = 9 ways again.
For 4 and 5 => 8 ways and so on.

Sum = 10 + 9 + 9 + 8 + 8 + 7 + 7 + ... + 1 + 1 = 100.

Thus, Probability = 100/21C3.
23259
@sameersapre23 said:
Out of 21 tickets marked with numbers from 1 to 21, three are drawn at random. Find the probability that these three numbers are in A.P.100/21C399/21C3101/21C3none of these
100/ 21C3 ?
23260
@sameersapre23 said:
Out of 21 tickets marked with numbers from 1 to 21, three are drawn at random. Find the probability that these three numbers are in A.P.100/21C399/21C3101/21C3none of these
100/21C3?

APs will be 19 + 17 + 15 + ... + 1

regards
scrabbler
23261
@YouMadFellow said:
Two dice are thrown simultaneously. The probability of getting a multiple of 2 on one dice and a multiple of 3 on other is: A. 1/6 B. 1/3 C. 5/12 D. 11/36 (No OA )
2 times (2, [3,6]) , (4, [3,6]), (6, [3,6]) => 2*6 = 12 - 1 (For 6,6 )

Thus, 11/36
23262
@sameersapre23 said:
Out of 21 tickets marked with numbers from 1 to 21, three are drawn at random. Find the probability that these three numbers are in A.P.100/21C399/21C3101/21C3none of these
100/21C3 ?
23263
@sameersapre23 said:
Aryan and Nandini are siblings. They participated in two different competition i.e. swimming and wrestling respectively. Aryan participated in swimming and Nandini in wrestling. Both were awarded rank between 1 to 50 (including 1 and 50). What is the probability that difference between their ranks is not more than 10 rank?9 / 2517 / 4040 / 1003 / 10
9/25
23264
@sameersapre23 said:
Out of 21 tickets marked with numbers from 1 to 21, three are drawn at random. Find the probability that these three numbers are in A.P.100/21C399/21C3101/21C3none of these
Total = 21C3

a-d, a, a+d are three terms in AP.

a can take values from 2 to 20.

When a = 2, d = 1 (1 possibility)
When a = 3, d = 1,2 (2 possibilities)
When a = 4, d = 1,2,3 (3 possibilities)
and so on..
When a = 10, d = 1,2,3,..9 (9 possibilities)
When a = 11, d = 1,2...10 (10 possibilities)
and so on..
When a = 20, d = 1 (1 possibility)

So, Favorable = (1+2+...9)*2 + 10 = 100

Prob = 100/21C3 ?
23265
@sameersapre23 said:
Ten people A, B, C, D, E, F, G, H, I and J attend a conference. F wants to speak before A, B wants to speak after A, C wants to speak after B and D wants to speak after C. In how many distinct orders can the 10 people speak?10!10c55! 10c5NONE OF THESE
F > A > B > C > D.

a + b + c + d + e + f = 5
So, 10 C 5 ways. and 5! for arranging them.

Thus, 10C5 * 5! ways.
23266
@YouMadFellow said:
Two dice are thrown simultaneously. The probability of getting a multiple of 2 on one dice and a multiple of 3 on other is: A. …™ B. …“ C. 5/12 D. 11/36
11/36