Maths P5
posted by jo .
Cindy went to the store with just enough money to buy 11 files.However, she bought only 8 files and spent the rest of her money on 24 pens and rulers. The ratio of the number of pens to rulers was 3:5. Each ruler costs $0.80. Each pen costs $0.40 more than a ruler.How much did she spent on the files?

pens  3x
rulers  5x
3x+5x= 24
8x=24
x=3
so she bought 9 pens and 15 rulers
amount spent on pens and rulers = 9(1.20) + 15(.80) = 22.80
money spent on files : money spent on pens&rulers = 8:3
money spent on files/22.8 = 8/3
= 60.80