The ratio of the number of croissants to the number of cookies in a shop is 3 : 1. A croissant costs $1.20 and a cookie costs $0.60. If all the croissants and cookies are sold, a sum of $42 will be collected. How many croissants are there altogether?
| |
Croissants |
Cookies |
Total |
| Number |
3 u |
1 u |
|
| Value |
$1.20 |
$0.60 |
|
| Total value |
3.6 u |
0.6 u |
$42 |
Amount collected if all the croissants are sold
= 3 u x 1.2
= 3.6 u
Amount collected if all the cookies are sold
= 1 u x 0.6 u
= 0.6 u
Amount collected if all the croissants and cookies are sold
= 3.6 u + 0.6 u
= 4.2 u
4.2 u = 42
1 u = 42 ÷ 4.2 = 10
Total number of croissants
= 3 u
= 3 x 10
= 30
Answer(s): 30
