Dewayne is comparing two checking accounts. One has a monthly fee of $7 and a per-check fee of $0.30, and the other has a monthly fee of $4 and a per-check fee of $0.40. What is the minimum number of checks Dewayne needs to write for the first bank to be a better option?

Question

A. 29.

B. 28.

C. 30.

D. 31.

Answer 1

we want
7.00 + .30x < 4.00 + .40x
3.00 < .10x
30 < x

so, if Dewayne writes more than 30 checks, the first bank costs less.

check: at 30 checks, the two banks cost the same:
7.00 + .30*30 = 7+9 = 16.00
4.00 + .40*30 = 4 + 12 = 16.00

after that, since bank 1 charges less per check, it will be a better deal.

Answer 2

31