The ratio of the number of cookies to the number of biscuits in a stall is 2 : 1. A cookie costs $1.90 and a biscuit costs $0.50. If all the cookies and biscuits are sold, a sum of $43 will be collected. How many cookies are there altogether?
| |
Cookies |
Biscuits |
Total |
| Number |
2 u |
1 u |
|
| Value |
$1.90 |
$0.50 |
|
| Total value |
3.8 u |
0.5 u |
$43 |
Amount collected if all the cookies are sold
= 2 u x 1.9
= 3.8 u
Amount collected if all the biscuits are sold
= 1 u x 0.5 u
= 0.5 u
Amount collected if all the cookies and biscuits are sold
= 3.8 u + 0.5 u
= 4.3 u
4.3 u = 43
1 u = 43 ÷ 4.3 = 10
Total number of cookies
= 2 u
= 2 x 10
= 20
Answer(s): 20
