A flower arrangement consists of 30 roses

[I_need_a_700plus]

Hello,

The following problem can found in GMAT Prep, practice exam.

A flower arrangement consists of 30 roses, each of which is either white or red. If a rode is to be selected at random from the flower arrangement, the probability will be white is twice the probability that it will be red. How many white roses are in the flower arrangement?

a) 5
b) 10
c) 15
d) 20
e) 25

Is my approach correct?

W + R = 30
W = 2R

Then substitution: 2R + R = 30; 3R = 30; R = 10

Therefore, W = 20?

Thanks!

[RonPurewal]

Yep