The ratio of the number of cookies to the number of biscuits in a shop is 4 : 1. A cookie costs $1.90 and a biscuit costs $0.70. If all the cookies and biscuits are sold, a sum of $166 will be collected. How many cookies are there altogether?
| |
Cookies |
Biscuits |
Total |
| Number |
4 u |
1 u |
|
| Value |
$1.90 |
$0.70 |
|
| Total value |
7.6 u |
0.7 u |
$166 |
Amount collected if all the cookies are sold
= 4 u x 1.9
= 7.6 u
Amount collected if all the biscuits are sold
= 1 u x 0.7 u
= 0.7 u
Amount collected if all the cookies and biscuits are sold
= 7.6 u + 0.7 u
= 8.3 u
8.3 u = 166
1 u = 166 ÷ 8.3 = 20
Total number of cookies
= 4 u
= 4 x 20
= 80
Answer(s): 80
