Problema Solution

Mary has $51.00 in ones and fives. She has a total of 23 bills. How many of each kind of bill does she have?

Answer provided by our tutors

let x=ones and y=fives

so x+y=23 ATQ

and 

x+5y=51

subtract both equations,we get

4y=28  so y=7(bills of fives)

x=23-7=16(bills of ones)