Question

Steven needed to mail a holiday envelope to his Aunt Linda. He used $0.02 stamps and $0.10 stamps to mail the gift. If he used 15 stamps worth $0.78, how many of each type of stamp did he use?

Answer 1

Answer:Steven used 9 $0.02 stamps and 6 $0.10 stamps

Explanation:

let number of $0.02 stamp be =x

let number of $0.10 stamp be =y

so that the number of stamps used can be expressed as

x+y=15

and the total price of stamps used equaling $0.78 be expressed as

0.02x + 0.10y =0.78

Solving

x+y=15----1

0.02x + 0.10y =0.78---2

from equation 1 , x =15-y, putting the value of x into equation 2

0.02(15-y) + 0.10y =0.78

0.3 -0.02y + 0.10y = 0.78

0.3 + 0.08y=0.78

0.08y=0.78-0.3

y=0.48/0.08 =6

y =6 stamps

Putting bthe value of y =6 into equation 1

x+6=15

x=15-6 =9

Steven used 9 $0.02 stamps and 6 $0.10 stamps