The ratio of the number of biscuits to the number of scones in a stall is 3 : 1. A biscuit costs $1.70 and a scone costs $0.40. If all the biscuits and scones are sold, a sum of $220 will be collected. How many biscuits are there altogether?
| |
Biscuits |
Scones |
Total |
| Number |
3 u |
1 u |
|
| Value |
$1.70 |
$0.40 |
|
| Total value |
5.1 u |
0.4 u |
$220 |
Amount collected if all the biscuits are sold
= 3 u x 1.7
= 5.1 u
Amount collected if all the scones are sold
= 1 u x 0.4 u
= 0.4 u
Amount collected if all the biscuits and scones are sold
= 5.1 u + 0.4 u
= 5.5 u
5.5 u = 220
1 u = 220 ÷ 5.5 = 40
Total number of biscuits
= 3 u
= 3 x 40
= 120
Answer(s): 120
