Kathy bought some gifts for her siblings at an average price of $12.90. If Kathy decided to buy a pen which cost $13 for her father and a bag which cost $47 for her mother, the average price of the gifts would become $14.80. How many gifts did Kathy buy for her siblings?
| |
Siblings |
Siblings and parents |
| Number |
1 u |
1 u + 2 |
| Value |
12.90 |
14.80 |
| Total Value |
12.90 u |
14.80 u + 29.60 |
Number of gifts that Kathy bought for her siblings = 1 u
Amount that Kathy spent on the gifts for her siblings
= 1 u x 12.90
= 12.90 u
Amount that $(Lizy) spent if she bought for her parents
= 13 + 47
= $60
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
= 14.80(1 u + 2)
= 14.80 u + 29.60
12.9 u + 60 = 14.80 u + 29.60
14.80 u - 12.9 u = 60 - 29.60
1.9 u = 30.40
1 u = 30.40 ÷ 1.9 = 16
Number of gifts that she bought for her siblings
= 1 u
= 16
Answer(s): 16
