BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

probability question

Expert replies
by sana.noor » Mon Mar 04, 2013 10:22 am
Each employee at a certain bank is either a clerk or an agent or both. Of every three agents, one is also a clerk. Of every two clerks, one is also an agent. what is the probability that an employee randomly selected from the bank is both an agent and a clerk?
a)1/2
b)1/3
c)1/4
d)1/5
e)2/5

C

Source: Nova Math
Work hard in Silence, Let Success make the noise.

If you found my Post really helpful, then don't forget to click the Thank/follow me button. :)
Join the discussion
Source: — Problem Solving |

by hemant_rajput » Mon Mar 04, 2013 10:35 am
Of every three agents, one is also a clerk. Let A, B and C are agents and one of them is clerk too, say B.

Of every two clerks, one is also an agent. Let B and D are clerks. Now we know that B is agent too, Now B and D are in accordance with the mentioned statement.

total outcome = 4 [A,B,C,D]
Favorable outcome = 1, i.e. B

1/4

Answer is C
I'm no expert, just trying to work on my skills. If I've made any mistakes please bear with me.
Join the discussion

by Anurag@Gurome » Mon Mar 04, 2013 9:27 pm
sana.noor wrote:Each employee at a certain bank is either a clerk or an agent or both. Of every three agents, one is also a clerk. Of every two clerks, one is also an agent. what is the probability that an employee randomly selected from the bank is both an agent and a clerk?
For each person who is both agent and clerk, we have two agents and one clerk.
Hence, among (1 + 2 + 1) = 4 people there is only one person who is both agent and clerk.

Required probability = 1/4

The correct answer is C.
Anurag Mairal, Ph.D., MBA
GMAT Expert, Admissions and Career Guidance
Gurome, Inc.
1-800-566-4043 (USA)

Join Our Facebook Groups
GMAT with Gurome
https://www.facebook.com/groups/272466352793633/
Admissions with Gurome
https://www.facebook.com/groups/461459690536574/
Career Advising with Gurome
https://www.facebook.com/groups/360435787349781/
Join the discussion