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

Redeem

GMAT Prep Question

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Senior | Next Rank: 100 Posts
Posts: 44
Joined: Mon Feb 25, 2008 10:36 pm

GMAT Prep Question

by jaydeer44 » Fri Mar 21, 2008 4:15 pm
Does anyone know the best way to solve this DS problem?

If m, r, x, and y are positive, is the ratio of m to r equal to the ratio of x to y?

(1) the ratio of m to y is equal to the ratio of x to r.

(2) the ratio of m + x to r + y is equal to the ratio of x to y.


The answer is B.
Top
Source: — Data Sufficiency |
Senior | Next Rank: 100 Posts
Posts: 34
Joined: Tue Sep 19, 2006 12:00 am
Thanked: 5 times
Followed by:9 members

by prachipareekh » Wed Mar 26, 2008 11:08 pm
Remember:

if p/q = r/s then
p+r/q+s = p/q = r/s
p-r/q-s = p/q = r/s
ps = qr

From statement(1): m/y = x/r -- insufficient we cannot find value of m/r
From statement(2): (m+x)/(r+y) = x/y
=> my+xy = xr+xy
=> my = xr
=> m/r = x/y -- sufficient

Hence ans B
Top
Master | Next Rank: 500 Posts
Posts: 468
Joined: Sat Mar 03, 2007 10:17 pm
Thanked: 5 times

by moneyman » Thu Mar 27, 2008 5:27 am
If m, r, x, and y are positive, is the ratio of m to r equal to the ratio of x to y?

(1) the ratio of m to y is equal to the ratio of x to r.

(2) the ratio of m + x to r + y is equal to the ratio of x to y.


We have to find out if m/r=x/y which means we have to find out if my=xr

(1) is not sufficient because it says m/y=x/r or mr=xy

(2) is SUFFICIENT because it says m+x/r+y=x/y or ym+xy=rx+yx(by cross multiplying)

xy cancels on both sides and we get my=xr
Maxx
Top
Post new topic Post Reply
• Page 1 of 1