Company X

This topic has expert replies
Senior | Next Rank: 100 Posts
Posts: 36
Joined: Mon Jun 09, 2008 9:17 am
Thanked: 2 times

Company X

by arbiter » Sun Aug 23, 2009 7:26 am
All the clients that company X had at the beginning of last year remained with the company for the whole year. If company X acquired new clients during the year, what was the ratio of the number of clients that company X had at the end of last year to the number of clients that it had at the beginning of last year?

1> the ratio of the number of clients taht company X had at the beginning of last year to the number of new clients that it acquired during the year was 12 to 1.

2> company x had 144 clients at the beginning of last year.

OA is A
arbiter
Source: — Data Sufficiency |

Master | Next Rank: 500 Posts
Posts: 134
Joined: Sun Feb 15, 2009 7:44 pm
Thanked: 14 times

by m&m » Sun Aug 23, 2009 12:28 pm
Imageine the following line chart as a calendar


begining|---------------------------------------|end
..........|
X customer|...........acquired Y customers

so (begining + throughout) / begining

looking at A we know that begining/throughout = 12z/1z
-- where z is some multiple, since we don't know if it was 12 and 1 or 24 and 2 or 36 and 3...

so (12z+z)/12z = 13z/12z = 13/12

A is sufficient

in 2 - knowing the total number does not help give proportion of each so insufficient

Hope that helps

Senior | Next Rank: 100 Posts
Posts: 73
Joined: Tue Aug 11, 2009 2:30 am
Thanked: 2 times
GMAT Score:720

by shanrizvi » Sun Aug 23, 2009 12:59 pm
Lets define some variables:

E = Clients at year-end
S = Clients at year-start
N = Clients acquired during the year

Clients at year-end = Clients at year-start + Clients acquired during the year

E = S + N

The question is asking for the ratio E:S.

Statement 1 gives us the ratio S:N (12:1). If there are 12 clients at the beginning of the year and 1 acquired during the year, the number of clients at year-end will be 13.

Hence, E:S = 13:12. Statement 1 is sufficient.

Statement 2 only tells us the total number of clients at the beginning of the year and without more information, we cannot calculate anything.