Official Quant thread for CAT 2013

MBA CAT 2024
6321
@grkkrg said:
A bag contains 3 Red, 2 Green and 4 Yellow balls. A ball is drawn and if it is Red or Yellow it is replaced otherwise not. Find the probability that second ball drawn is a yellow ball.No no... The ball you take out the second time is the "second ball drawn"..
29/99?
6322
A=(25^86) - (5^171)
How many digits would be there in A when it is represented in base 5?
6323
@19rsb said:
A=(25^86) - (5^171)How many digits would be there in A when it is represented in base 5?
172??
6324
@19rsb said:
A=(25^86) - (5^171)How many digits would be there in A when it is represented in base 5?
172?
6325
@19rsb said:
A=(25^86) - (5^171)How many digits would be there in A when it is represented in base 5?
172 digits
6326
@maneeshp said:
A, B and C in order, toss a coin. The one who gets a head first wins. Find their respective probabilities of winning. 4/7,2/7,1/7Can anyone explain this??
getting a head= 1/2

suppose A win.
It can happen as
1/2 or 1/2*1/2*1/2*1/2(if A B C looses in a row and A win next time.) or 1/2^7 or..... [upto infinity]

so it is a infinite GP of form, with first term= 1/2 and r= 1/2^3

1/2+ 1/2^4 + 1/2^7 + .....
Prob of A win = 1/2/(1- 1/2^3) = 4/7

similarly for B a=1/4 and r= 1/8
Prob (B)= 2/7

and for C a= 1/8 and r= 1/2^3
Prob (C)= 1/7
6327
@19rsb said:
A=(25^86) - (5^171)How many digits would be there in A when it is represented in base 5?
172 digits
6328
You are given the responsibility of organizing a fresher's welcome party at IIM-A. Total 496 students will join IIM-A. Six restaurants A, B, C, D, E and F are booked. Capacity of each is 120, 146, 46, 72, 72, 80 persons at a time respectively. You have to group them in such a way that each group has least possible number of students.Number of ways of doing so?

6329
@19rsb said:
A=(25^86) - (5^171)How many digits would be there in A when it is represented in base 5?
172 digits
6330
@pankaj1988 said:
You are given the responsibility of organizing a fresher's welcome party at IIM-A. Total 496 students will join IIM-A. Six restaurants A, B, C, D, E and F are booked. Capacity of each is 120, 146, 46, 72, 72, 80 persons at a time respectively. You have to group them in such a way that each group has least possible number of students.Number of ways of doing so?
??
P.S. Only 1 way will be there na in which every group has least possible?? smjh ni aya q
6331
@pankaj1988 said:
You are given the responsibility of organizing a fresher's welcome party at IIM-A. Total 496 students will join IIM-A. Six restaurants A, B, C, D, E and F are booked. Capacity of each is 120, 146, 46, 72, 72, 80 persons at a time respectively. You have to group them in such a way that each group has least possible number of students.Number of ways of doing so?
blind shot... 15 by any chance? or 15*4!= 360 if take arrangement.
please tag we with the OA.
6332
@grkkrg said:
A bag contains 3 Red, 2 Green and 4 Yellow balls. A ball is drawn and if it is Red or Yellow it is replaced otherwise not. Find the probability that second ball drawn is a yellow ball.No no... The ball you take out the second time is the "second ball drawn"..
37/81?
6333
@19rsb said:
A=(25^86) - (5^171)How many digits would be there in A when it is represented in base 5?
173?
5^172 has 173 digits
6334
@19rsb said:
A=(25^86) - (5^171)How many digits would be there in A when it is represented in base 5?
1000...170zeros..4
No of digits=172
6335
A music class has a group of 5 students.Three sub groups(X,Y,Z) are formed by choosing the student at random from main group.Same student can be put into two or more groups as well.What is the probability that no student is common in all the three sub groups?
6336
@19rsb said:
A music class has a group of 5 students.Three sub groups(X,Y,Z) are formed by choosing the student at random from main group.Same student can be put into two or more groups as well.What is the probability that no student is common in all the three sub groups?
This was posted yesterday . ans is (7/8)^5 .
6337
@wovfactorAPS said:
173?5^172 has 173 digits
I think u r making some calculation mistake......bcoz A will b equal to 5^171 x 4
convert it into base 5 ..........OA is 172
6338
@maddy2807 @ScareCrow28
Bhai chk out this link...
http://www.askiitians.com/iit-jee-algebra/permutations-and-combinations/solved-examples-page5.aspx
Very clear and nice soln...
6339
@wovfactorAPS said:
173?5^172 has 173 digits
you are correct. A will have 173 digits and B will have 172 digits. But their difference would have 172 digits.

this is similar to: 100 (has 3 digits) and 10 (has 2 digits) and their difference is 90 (which is 2 digits.

A will be 1 followed by 172 zeros and B will be 1 followed by 171 zeros.

Hope this helps.

ATDH

6340
How many necklaces of 10 beads each can be made from 20 beads of different colours?

ofc