Storage Capacity

This topic has expert replies
Newbie | Next Rank: 10 Posts
Posts: 2
Joined: Fri Jun 27, 2008 8:52 pm
Location: Dallas

Storage Capacity

by mdun62 » Fri Dec 12, 2008 8:57 pm
The Storage capacity of disk drive A is 85% that of disk drive B. What percentage of drive B's storage capacity is currently used?

1. Disk drive B holds 3 more gigabytes than disk drive A.
2. 8.5 gigabytes of disk drive B's storage capacity is currently used.

The answer is C.

Can someone explain the steps.
PMGirl
Source: — Data Sufficiency |

User avatar
Community Manager
Posts: 1049
Joined: Sun Apr 06, 2008 5:15 pm
Location: Pittsburgh, PA
Thanked: 113 times
Followed by:27 members
GMAT Score:710

by dmateer25 » Fri Dec 12, 2008 9:22 pm
From the question we are given:

A=.85B

Stmt 1)

A = B - 3


Now we can determine the capacity of both storage devices:

B - 3 = .85B
.15B = 3
B = 3/.15
B=20

A = B - 3
A = 17

We now know the storage capacity. However, we don't know how much of B's capacity is used.

Insuff

2) From this we can't determine the size of A or B

Insuff

Together:

We know B = 20 from Stmt 1. We know 8.5 is used from Stmt 2.

8.5/20 = 42.5% of B's capacity is used

C