Jason went to the post office and bought both 41-cent stamps and 26-cent postcards and spent $10.28. The number of stamps was 4 more than twice the number of postcards. How many of each did he buy?

Solution:

Let stamps be s and postcards be p

Given that,

The number of stamps was 4 more than twice the number of postcards

s = 4 + 2p -------- eqn 1

Jason bought both 41-cent stamps and 26-cent postcards and spent $10.28

41 cent = $ 0.41

26 cent = $ 0.26

Therefore,

0.41s + 0.26p = 10.28 --------- eqn 2

Substitute eqn 1 in eqn 2

0.41(4 + 2p) + 0.26p = 10.28

1.64 + 0.82p + 0.26p = 10.28

1.08p = 10.28 - 1.64

1.08p = 8.64

Divide both sides by 1.08

p = 8

Substitute p = 8 in eqn 1

s = 4 + 2(8)

s = 4 + 16

s = 20

Thus Jason bought 20 stamps and 8 post cards