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

Redeem

GMATprep PS question

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Source: — Problem Solving |
Junior | Next Rank: 30 Posts
Posts: 28
Joined: Mon Jun 30, 2008 1:45 pm
Thanked: 3 times

by szapiszapo » Wed Jul 02, 2008 12:16 am
Answer is E (i.e. 6/7)


We know from the wording that
a2 = 2*a1
a3 = 2*a2
a4 = 2*a3
and so on

thus a5 = 2*a4 = 2*2*a3 = 2*2*2*a2 = 8*a2

We also know from the wording that
a5 - a2 = 12

replacing a5 by 8*a2 gives us
a2 = 12/7

now, with a2 = 2*a1, we find a1 = 6/7
Top
Post new topic Post Reply
• Page 1 of 1