How many of each kind of stamp does he have?

Question

Mr. Akika has 36 18 cent and 30 cent stamps all told. The stamps are worth $9.48. How many each kind of stamps does he have?

Answer 1

x+y = 36

18x + 30y = 948

18x + 18y = 18(36) = 648

12y = 948-648 = 300

y = 300/12 = 25 30 cent stamps

x= 11 18 cent stamps

11(18) + 25(30) = 198 + 750 = 948