Tiffany bought some gifts for her siblings at an average price of $13.70. If Tiffany decided to buy a pen which cost $17 for her father and a bag which cost $38 for her mother, the average price of the gifts would become $18.30. How many gifts did Tiffany buy for her siblings?
| |
Siblings |
Siblings and parents |
| Number |
1 u |
1 u + 2 |
| Value |
13.70 |
18.30 |
| Total Value |
13.70 u |
18.30 u + 36.60 |
Number of gifts that Tiffany bought for her siblings = 1 u
Amount that Tiffany spent on the gifts for her siblings
= 1 u x 13.70
= 13.70 u
Amount that $(Lizy) spent if she bought for her parents
= 17 + 38
= $55
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
= 18.30(1 u + 2)
= 18.30 u + 36.60
13.7 u + 55 = 18.30 u + 36.60
18.30 u - 13.7 u = 55 - 36.60
4.6 u = 18.40
1 u = 18.40 ÷ 4.6 = 4
Number of gifts that she bought for her siblings
= 1 u
= 4
Answer(s): 4
