Elyse wanted to buy some biscuits and puffs. The cost of a biscuit was
37 the cost of a puff. A set of 6 biscuits and 3 puffs cost $7.80. What was the total amount Elyse had to pay for 9 biscuits and 10 puffs?
| |
Biscuits |
Puffs |
Total |
| Number |
6 |
3 |
|
| Value |
3 u |
7 u |
|
| Total value |
18 u |
21 u |
39 u |
Total cost of biscuits and puffs
= 18 u + 21 u
= 39 u
39 u = 7.8
1 u = 7.80 ÷ 39 = 0.2
Cost of 9 biscuits and 10 puffs
= 9 x 3 u + 10 x 7 u
= 27 u + 70 u
= 97 u
= 97 x 0.2
= $19.40
Answer(s): $19.40
