probab

This topic has expert replies
Master | Next Rank: 500 Posts
Posts: 371
Joined: Tue Apr 29, 2008 10:16 am
Thanked: 6 times
Followed by:1 members

probab

by vaivish » Wed Jun 25, 2008 8:20 am
In Company X, the number of male employee is twice the number of female employees. The number of male employees who have a master degree is equal to the number of female employees who have a master degree. If 1/5 of the employees in Company X have a master degree, then, what fraction of the male employees do not have a master degree?
(A) 1/5
(B) 2/5
(C) 3/20
(D) 7/10
(E) 17/20

User avatar
Legendary Member
Posts: 566
Joined: Fri Jan 04, 2008 11:01 am
Location: Philadelphia
Thanked: 31 times
GMAT Score:640

by AleksandrM » Wed Jun 25, 2008 9:15 am
Set up a matrix:

Work with easy numbers. If there are 50 women, then there are 100 men, = 150 total empoyees.

1/5 of 150 = 30 half of which (15) is men with MS and half female with MS.

Now fill in the rest of your matrix.

Men without an MS = 100 - 15 = 85

Don't need it, but female without an MS = 35.

Anyway, to answer the question:

85/100 reduces to 17/20.

Choose E.

Master | Next Rank: 500 Posts
Posts: 132
Joined: Sun Apr 27, 2008 10:31 am
Location: Portugal
Thanked: 7 times

by atlantic » Wed Jun 25, 2008 9:40 am
Hi Vavish,

M - total number of male employees
F - total number of female employees
Mm - number of male employees with master degree
Fm - number of female employees with master degree

From the statement we know that

(1) M=2F <-> F=1/2M
(2) Mm=Fm
(3) Mm+Fm=1/5(M+F)

Then Mm+Fm=1/5(M+F) <-> 2Mm=1/5(M+1/2M) <-> 2Mm=3/10M

<-> Mm/M=3/20 that can be read as the fraction of male with a master degree.

Obviously, the fraction of male without a master degree is 1-Mm/M = 17/20

Answer E.

Hope it helps.

Master | Next Rank: 500 Posts
Posts: 371
Joined: Tue Apr 29, 2008 10:16 am
Thanked: 6 times
Followed by:1 members

by vaivish » Wed Jun 25, 2008 11:03 am
ya its right