Problema Solution
1. Christi's mother gave her $9 to buy 10cents and 15cents stamps. Christi returned with $1.75 in change and a total of 60 stamps. How many of each kind of stamp does she buy?
Answer provided by our tutors
0.10 is 10cents
0.15 is 15cents
let 'x' represent the number of 10cent pieces, then '60-x' represents the number of 15cents
(9-1.75)=0.10x + 0.15(60-x)
click here to solve for the number of 10cent pieces
x=35
60-35=25
So Christi purchased 35 10cents and 25 15cents.