Posted by Megan Brown on .
How would you work, and solve this problem?
Christa is a waitress and collects her tips at the table. At the end of the shift she has 68 bills, all ones and fives. If the total value of her tips is 172, how many of each bill does she have?

Math 
helper,
n = number of ones
1n = value of ones
68  n = number of fives
5(68  n) = value of fives
n + 5(68  n) = 172
n + 340  5n = 172
4n = 168
n = 42
n = 42 ones = 42.00
68  n = 26 fives = 130.00
68 bills = 172