The ratio of the number of wafers to the number of scones in a kiosk is 3 : 1. A wafer costs $1.10 and a scone costs $0.90. If all the wafers and scones are sold, a sum of $42 will be collected. How many wafers are there altogether?
| |
Wafers |
Scones |
Total |
| Number |
3 u |
1 u |
|
| Value |
$1.10 |
$0.90 |
|
| Total value |
3.3 u |
0.9 u |
$42 |
Amount collected if all the wafers are sold
= 3 u x 1.1
= 3.3 u
Amount collected if all the scones are sold
= 1 u x 0.9 u
= 0.9 u
Amount collected if all the wafers and scones are sold
= 3.3 u + 0.9 u
= 4.2 u
4.2 u = 42
1 u = 42 ÷ 4.2 = 10
Total number of wafers
= 3 u
= 3 x 10
= 30
Answer(s): 30
