The ratio of the number of biscuits to the number of puffs in a supermarket is 3 : 1. A biscuit costs $1.80 and a puff costs $0.80. If all the biscuits and puffs are sold, a sum of $62 will be collected. How many biscuits are there altogether?
| |
Biscuits |
Puffs |
Total |
| Number |
3 u |
1 u |
|
| Value |
$1.80 |
$0.80 |
|
| Total value |
5.4 u |
0.8 u |
$62 |
Amount collected if all the biscuits are sold
= 3 u x 1.8
= 5.4 u
Amount collected if all the puffs are sold
= 1 u x 0.8 u
= 0.8 u
Amount collected if all the biscuits and puffs are sold
= 5.4 u + 0.8 u
= 6.2 u
6.2 u = 62
1 u = 62 ÷ 6.2 = 10
Total number of biscuits
= 3 u
= 3 x 10
= 30
Answer(s): 30
