Question

Tony is comparing two checking accounts. One has a monthly fee of $15 and a per-check fee of $0.20, and the other has a monthly fee of $20 and a per-check fee of $0.10. What is the minimum number of checks Tony needs to write for the second bank to be a better option?

Answer 1

He should write at least 51 checks because 
51*0.2  10.2 
10.2+ 15 =25.2

51* 0.1 = 5.1
5.1 + 20  = 25.1 which makes check 2 a better option.