At the beginning of 2011, Albert invests $15,000 at 10% simple annual interest, $6,000 at 7% simple annual interest, and

This topic has expert replies
Moderator
Posts: 2505
Joined: Sun Oct 15, 2017 1:50 pm
Followed by:6 members

Timer

00:00

Your Answer

A

B

C

D

E

Global Stats

Source: Manhattan Prep

At the beginning of 2011, Albert invests $15,000 at 10% simple annual interest, $6,000 at 7% simple annual interest, and $x at 8% simple annual interest. If, by the end of 2011, Albert receives interest totaling 9% of the sum of his three investments, then the ratio of $x to the sum of his two other investments is

A. 1:3
B. 1:4
C. 1:6
D. 1:7
E. 1:8

The OA is D
Source: — Problem Solving |

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 8086
Joined: Sat Apr 25, 2015 10:56 am
Location: Los Angeles, CA
Thanked: 43 times
Followed by:29 members
BTGmoderatorLU wrote:
Wed Jan 27, 2021 11:35 am
Source: Manhattan Prep

At the beginning of 2011, Albert invests $15,000 at 10% simple annual interest, $6,000 at 7% simple annual interest, and $x at 8% simple annual interest. If, by the end of 2011, Albert receives interest totaling 9% of the sum of his three investments, then the ratio of $x to the sum of his two other investments is

A. 1:3
B. 1:4
C. 1:6
D. 1:7
E. 1:8

The OA is D

Solution:

Using the formula Interest = Rate x Time, we can create the equation for the total interest earned by the 3 investments, letting x equal the amount invested at 8% simple interest:

15,000 * 0.1 + 6,000 * 0.07 + x * 0.08 = (15,000 + 6,000 + x) * 0.09

1,500 + 420 + 0.08x = 1,890 + 0.09x

30 = 0.01x

3,000 = x

Therefore, the desired ratio is 3,000 : (15,000 + 6,000) = 3,000 : 21,000 = 1:7.

Answer: D

Scott Woodbury-Stewart
Founder and CEO
[email protected]

Image

See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews

ImageImage