Mathematics Question

Question

A bank teller has 46 $5 and $20 bills in her cash drawer. The value of the bills is $695. How many $5 bills are there?

Answer 1

T = # of twenties

F = # of fives

Counting the bills we get:

(1) T + F = 46

From the total value of 695 we get:

(2) 20T + 5F = 695

Eq (1) implies T = 46-F. Substitute this into (2) to get one equation with just F as the unknown, then solve for F.

I got F = 15 (so T = 31, and the total value does check out at 695).