The ratio of the number of biscuits to the number of cookies in a kiosk is 2 : 1. A biscuit costs $1.60 and a cookie costs $0.70. If all the biscuits and cookies are sold, a sum of $78 will be collected. How many biscuits are there altogether?
| |
Biscuits |
Cookies |
Total |
| Number |
2 u |
1 u |
|
| Value |
$1.60 |
$0.70 |
|
| Total value |
3.2 u |
0.7 u |
$78 |
Amount collected if all the biscuits are sold
= 2 u x 1.6
= 3.2 u
Amount collected if all the cookies are sold
= 1 u x 0.7 u
= 0.7 u
Amount collected if all the biscuits and cookies are sold
= 3.2 u + 0.7 u
= 3.9 u
3.9 u = 78
1 u = 78 ÷ 3.9 = 20
Total number of biscuits
= 2 u
= 2 x 20
= 40
Answer(s): 40
