A cake cost twice as much as a doughnut at a nearby coffee shop. Zane spent 16 of his money on some doughnuts and half of the remaining sum on 5 cakes. He had $25 left.
- What was the cost of 1 doughnut?
- Peter bought 3 cakes and 4 doughnuts. How much did he spend altogether?
(a)
Fraction of Zane's amount left after buying the doughnuts
= 1 -
16 =
56 Fraction of Zane's amount spent on the cakes
=
56 x
12 =
512 Fraction of money left
= 1 -
16 -
512 = 1 -
212 -
512 =
512 Amount that Zane had left = 5 u
5 u = 25
1 u = 25 ÷ 5 = 5
Amount that Zane had left = Amount spent on 5 cakes
Cost of 5 cakes = $25
Cost of 1 cake = 25 ÷ 5 = $5
Cost of 1 cake is 2 times as much as the cost of 1 doughnut.
Cost of 1 doughnut
= 5 ÷ 2
= $2.50
(b)
Cost of 3 cakes and 4 doughnuts
= 3 x 5 + 4 x 2.50
= 15 + 10
= $25
Answer(s): (a) $2.50; (b) $25
