A cake cost five times as much as a cookie at a nearby food outlet. Fred spent 14 of his money on some cookies and half of the remaining sum on 3 cakes. He had $18 left.
- What was the cost of 1 cookie?
- Billy bought 3 cakes and 5 cookies. How much did he spend altogether?
(a)
Fraction of Fred's amount left after buying the cookies
= 1 -
14 =
34 Fraction of Fred's amount spent on the cakes
=
34 x
12 =
38 Fraction of money left
= 1 -
14 -
38 = 1 -
28 -
38 =
38 Amount that Fred had left = 3 u
3 u = 18
1 u = 18 ÷ 3 = 6
Amount that Fred had left = Amount spent on 3 cakes
Cost of 3 cakes = $18
Cost of 1 cake = 18 ÷ 3 = $6
Cost of 1 cake is 5 times as much as the cost of 1 cookie.
Cost of 1 cookie
= 6 ÷ 5
= $1.20
(b)
Cost of 3 cakes and 5 cookies
= 3 x 6 + 5 x 1.20
= 18 + 6
= $24
Answer(s): (a) $1.20; (b) $24
