The ratio of the number of cookies to the number of scones in a supermarket is 3 : 1. A cookie costs $1.70 and a scone costs $0.50. If all the cookies and scones are sold, a sum of $168 will be collected. How many cookies are there altogether?
| |
Cookies |
Scones |
Total |
| Number |
3 u |
1 u |
|
| Value |
$1.70 |
$0.50 |
|
| Total value |
5.1 u |
0.5 u |
$168 |
Amount collected if all the cookies are sold
= 3 u x 1.7
= 5.1 u
Amount collected if all the scones are sold
= 1 u x 0.5 u
= 0.5 u
Amount collected if all the cookies and scones are sold
= 5.1 u + 0.5 u
= 5.6 u
5.6 u = 168
1 u = 168 ÷ 5.6 = 30
Total number of cookies
= 3 u
= 3 x 30
= 90
Answer(s): 90
