Emma bought 7 biscuits more than shortbreads. Each biscuit cost $0.70 while each shortbread cost $1.40. Given that she spent $23.80 in total, how many shortbreads did Emma buy?
| |
Shortbreads |
Biscuits |
Total |
| Number |
1 u |
1 u + 7 |
|
| Value |
$1.40 |
$0.70 |
|
| Total value |
1.4 u |
0.7 u + 4.9 |
0.7 u + 4.9 |
Amount that Emma paid for the shortbreads
= 1 u x 1.40
= 1.4 u
Amount that Emma paid for biscuits
= 0.7 x (1 u + 7)
= 0.7 u + 4.9
Total amount that Emma paid
= 1.4 u + 0.7 u + 4.9
= 2.1 u + 4.9
2.1 u + 4.9 = 23.8
2.1 u = 23.8 - 4.9
2.1 u = 18.9
1 u = 18.9 ÷ 2.1 = 9
Number of shortbreads that Emma bought
= 1 u
= 9
Answer(s): 9
