The ratio of the number of cookies to the number of macarons in a stall is 3 : 1. A cookie costs $1.90 and a macaron costs $0.70. If all the cookies and macarons are sold, a sum of $128 will be collected. How many cookies are there altogether?
| |
Cookies |
Macarons |
Total |
| Number |
3 u |
1 u |
|
| Value |
$1.90 |
$0.70 |
|
| Total value |
5.7 u |
0.7 u |
$128 |
Amount collected if all the cookies are sold
= 3 u x 1.9
= 5.7 u
Amount collected if all the macarons are sold
= 1 u x 0.7 u
= 0.7 u
Amount collected if all the cookies and macarons are sold
= 5.7 u + 0.7 u
= 6.4 u
6.4 u = 128
1 u = 128 ÷ 6.4 = 20
Total number of cookies
= 3 u
= 3 x 20
= 60
Answer(s): 60
