The ratio of the number of puffs to the number of shortbreads in a stall is 2 : 1. A puff costs $1.80 and a shortbread costs $0.30. If all the puffs and shortbreads are sold, a sum of $156 will be collected. How many puffs are there altogether?
|
Puffs |
Shortbreads |
Total |
Number |
2 u |
1 u |
|
Value |
$1.80 |
$0.30 |
|
Total value |
3.6 u |
0.3 u |
$156 |
Amount collected if all the puffs are sold
= 2 u x 1.8
= 3.6 u
Amount collected if all the shortbreads are sold
= 1 u x 0.3 u
= 0.3 u
Amount collected if all the puffs and shortbreads are sold
= 3.6 u + 0.3 u
= 3.9 u
3.9 u = 156
1 u = 156 ÷ 3.9 = 40
Total number of puffs
= 2 u
= 2 x 40
= 80
Answer(s): 80