The ratio of the number of cookies to the number of puffs in a shop is 3 : 1. A cookie costs $1.10 and a puff costs $0.50. If all the cookies and puffs are sold, a sum of $114 will be collected. How many cookies are there altogether?
| |
Cookies |
Puffs |
Total |
| Number |
3 u |
1 u |
|
| Value |
$1.10 |
$0.50 |
|
| Total value |
3.3 u |
0.5 u |
$114 |
Amount collected if all the cookies are sold
= 3 u x 1.1
= 3.3 u
Amount collected if all the puffs are sold
= 1 u x 0.5 u
= 0.5 u
Amount collected if all the cookies and puffs are sold
= 3.3 u + 0.5 u
= 3.8 u
3.8 u = 114
1 u = 114 ÷ 3.8 = 30
Total number of cookies
= 3 u
= 3 x 30
= 90
Answer(s): 90
