The average (arithmetic mean) of 3a + 4 and another number is 2a. What is the average of the other number and a ?
A. 2a
B. a - 4
C. a - 2
D. a + 2
E. a + 4
Answer: C
Source: Kaplan
The average (arithmetic mean) of 3a + 4 and another number is 2a. What is the average of the other number and a ?
This topic has expert replies
-
- Legendary Member
- Posts: 1223
- Joined: Sat Feb 15, 2020 2:23 pm
- Followed by:1 members
Timer
00:00
Your Answer
A
B
C
D
E
Global Stats
GMAT/MBA Expert
- Scott@TargetTestPrep
- GMAT Instructor
- Posts: 7243
- Joined: Sat Apr 25, 2015 10:56 am
- Location: Los Angeles, CA
- Thanked: 43 times
- Followed by:29 members
We can let n = the average of the other number and create the following equation:BTGModeratorVI wrote: ↑Tue Dec 15, 2020 6:58 amThe average (arithmetic mean) of 3a + 4 and another number is 2a. What is the average of the other number and a ?
A. 2a
B. a - 4
C. a - 2
D. a + 2
E. a + 4
Answer: C
Source: Kaplan
(3a + 4 + n)/2 = 2a
3a + 4 + n = 4a
4 + n = a
The average of the other number and a is:
(n + 4 + n)/2 = (2n + 4)/2 = n + 2
Since n = a - 4, we can say:
n + 2 = a - 4 + 2 = a - 2
Answer: C
Scott Woodbury-Stewart
Founder and CEO
[email protected]
See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews