Question 999540

May buys combination of stamps of 45 cent and 65 cent she spends 24.50 on 50 how many of each did she buy
<pre>Let number of .45 stamps purchased be F
Then number of 65c stamps purchased = 50 - F
We then get: .45F + .65(50 - F) = 24.5
.45F + 32.5 - .65F = 24.5
.45F - .65F = 24.5 - 32.5
- .2F = - 8
F, or number of 45c stamps purchased = {{{(- 8)/(- .2)}}}, or {{{highlight_green(40)}}}
Number of 65c stamps purchased: 50 - 40, or {{{highlight_green(10)}}}