BTGModeratorVI wrote: ↑Mon Sep 14, 2020 8:41 am
If a sequence of 8 consecutive odd integers with increasing values has 9 as its 7th term, what is the sum of the terms of the sequence?
(A) 22
(B) 32
(C) 36
(D) 40
(E) 44
Answer:
B
Source: Official guide
One way to solve is to use the following rule that says,
"In a set where the numbers are equally spaced, the mean will equal the median."
For example, in each of the following sets, the mean and median are equal:
{7, 9, 11, 13, 15}
{-1, 4, 9, 14}
{3, 4, 5, 6}
Since we the 8 consecutive odd integers are equally spaced, the median = the mean
The median of the 8 terms will be the average of term4 and term5.
Given: term7 = 9
So, term6 = 7
term5 = 5
term4 = 3
So, the median of the 8 terms = (5 + 3)/2 = 4
So, the MEAN of the 8 terms is also
4
If the mean of the
8 terms =
4, then the SUM of the 8 terms = (
8)(
4) = 32
Answer: B
Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
