The ratio of the number of cookies to the number of tarts in a supermarket is 6 : 1. A cookie costs $1.10 and a tart costs $0.50. If all the cookies and tarts are sold, a sum of $142 will be collected. How many cookies are there altogether?
| |
Cookies |
Tarts |
Total |
| Number |
6 u |
1 u |
|
| Value |
$1.10 |
$0.50 |
|
| Total value |
6.6 u |
0.5 u |
$142 |
Amount collected if all the cookies are sold
= 6 u x 1.1
= 6.6 u
Amount collected if all the tarts are sold
= 1 u x 0.5 u
= 0.5 u
Amount collected if all the cookies and tarts are sold
= 6.6 u + 0.5 u
= 7.1 u
7.1 u = 142
1 u = 142 ÷ 7.1 = 20
Total number of cookies
= 6 u
= 6 x 20
= 120
Answer(s): 120
