Source: Magoosh
When 12 marbles are added to a rectangular aquarium, the water in the aquarium rises 1 1/2 inches. In total, how many marbles must be added to the aquarium to raise the water 2 3/4 inches?
A. 16
B. 18
C. 20
D. 22
E. 24
The OA is D
5-Day Free Trial
5-day free, full-access trial TTP
Available with Beat the GMAT members only code
MORE DETAILS
When 12 marbles are added to a rectangular aquarium, the water in the aquarium rises 1 1/2 inches...
This topic has expert replies
-
BTGmoderatorLU
- Moderator
- Posts: 2207
- Joined: Sun Oct 15, 2017 1:50 pm
- Followed by:6 members
GMAT/MBA Expert
-
Brent@GMATPrepNow
- GMAT Instructor
- Posts: 16207
- Joined: Mon Dec 08, 2008 6:26 pm
- Location: Vancouver, BC
- Thanked: 5254 times
- Followed by:1268 members
- GMAT Score:770
We can solve this question using equivalent ratiosBTGmoderatorLU wrote: ↑Tue Feb 18, 2020 3:49 amSource: Magoosh
When 12 marbles are added to a rectangular aquarium, the water in the aquarium rises 1 1/2 inches. In total, how many marbles must be added to the aquarium to raise the water 2 3/4 inches?
A. 16
B. 18
C. 20
D. 22
E. 24
The OA is D
We'll use the ratio: #of marbles/rise (in inches)
Let x = the number of marbles required to raise the water 2 3/4 inches (aka 2.75 inches).
We can write: 12/1.5 = x/2.75
Cross multiply to get: (1.5)(x) = (12)(2.75)
Simplify: 1.5x = 33
Solve: x = 33/1.5 = 22
Answer: D
Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
