Wendy paid $19 for 3 cookies and 7 cakes. A cake cost five times as much as a cookie.
- Find the cost of a cookie in cents.
- How much more did she pay for a cake than a cookie?
| |
Cookies |
Cakes |
Total |
| Number |
3 |
7 |
|
| Value |
1 u |
5 u |
|
| Total value |
3 u |
35 u |
38 u |
(a)
Cost of 1 cookie = 1 u
Cost of 1 cake = 5 u
Cost of 3 cookies
= 3 x 1 u
= 3 u
Cost of 7 cakes
= 7 x 5 u
= 35 u
Total cost of 3 cookies and 7 cakes
= 3 u + 35 u
= 38 u
$1 = 100¢
$19 = 19 x 100 = 1900¢
38 u = 1900
1 u = 1900 ÷ 38 = 50
Cost of a bun
= 1 u
= 50¢
(b)
Amount that Wendy paid more for a cake than a cookie
= 3 u - 1 u
= 2 u
= 2 x 50
= 100¢
100¢ = $1
Answer(s): (a) 50¢ (b) $1
