find the value

Question

A motel clerk counts his $1 and $10 bills at the end of the day. He finds that he has a total of 60
bills having a combined monetary value of $195. Find the number of bills of each denomination that he has.

Answer 1

let x = the number of ones

y = the number of tens

 

x + y = 60

 

x + 10y = 195

 

x = 60 - y

 

(60 - y) + 10y = 195

 

60 + 9y = 195

 

9y = 135

 

y = 15

 

There are 15 tens and 60 - 15 = 45 ones