Question

postman sold some 15 cent stamps and some 25 cent stamps. 10 stamps total were sold for $1.70. How many of each were sold?

Answer 1

Let x = the number of 15 cent stamps sold
then 10 - x = number of 25 cent stamp sold

The total sold came to $1.70

15x + 25(10-x)=1.70
15x+250-25x=1.70
-10x=170-250-30
-10x=-80
x=8 15 cent stamps
10-8=2 25 cent stamps. $1.20 + .50 =$1.70

Answer 2

typo * -10x=170-250=80