Jeff Miller

GMAT OFFICIAL GUIDE PS – What is the difference between the sixth and the fifth terms…

What is the difference between the sixth and the fifth terms…

Solution:

For the sixth term, we need to substitute 6 for n, and for the fifth term, we need to substitute 5 for n. Then we’ll find the difference between the two terms.

Let’s first plug 6 in for n.

6 + 2^(6-1)

6 + 2^5

6 + 32 = 38

Next let’s plug 5 in for n.

5 + 2^(5-1)

5 + 2^4

5 + 16 = 21

Thus, the difference between the 6th and 5th term of the sequence is 38 – 21 = 17.

Answer: E