Emma bought some presents for her siblings at an average price of $10.10. If Emma decided to buy a pen which cost $17 for her father and a bag which cost $48 for her mother, the average price of the presents would become $15.70. How many presents did Emma buy for her siblings?
| |
Siblings |
Siblings and parents |
| Number |
1 u |
1 u + 2 |
| Value |
10.10 |
15.70 |
| Total Value |
10.10 u |
15.70 u + 31.40 |
Number of presents that Emma bought for her siblings = 1 u
Amount that Emma spent on the presents for her siblings
= 1 u x 10.10
= 10.10 u
Amount that $(Lizy) spent if she bought for her parents
= 17 + 48
= $65
Total number of items bought if she bought for her parents and her siblings
= 1 u + 1 + 1
= 1 u + 2
Total amount that she spent if she bought for her parents and her siblings
= 15.70(1 u + 2)
= 15.70 u + 31.40
10.1 u + 65 = 15.70 u + 31.40
15.70 u - 10.1 u = 65 - 31.40
5.6 u = 33.60
1 u = 33.60 ÷ 5.6 = 6
Number of presents that she bought for her siblings
= 1 u
= 6
Answer(s): 6
