Erika bought some gifts for her relatives at an average price of $12.80. If Erika decided to buy a pen which cost $12 for her father and a bag which cost $37 for her mother, the average price of the gifts would become $14.10. How many gifts did Erika buy for her relatives?
| |
Relatives |
Relatives and parents |
| Number |
1 u |
1 u + 2 |
| Value |
12.80 |
14.10 |
| Total Value |
12.80 u |
14.10 u + 28.20 |
Number of gifts that Erika bought for her relatives = 1 u
Amount that Erika spent on the gifts for her relatives
= 1 u x 12.80
= 12.80 u
Amount that $(Lizy) spent if she bought for her parents
= 12 + 37
= $49
Total number of items bought if she bought for her parents and her relatives
= 1 u + 1 + 1
= 1 u + 2
Total amount that she spent if she bought for her parents and her relatives
= 14.10(1 u + 2)
= 14.10 u + 28.20
12.8 u + 49 = 14.10 u + 28.20
14.10 u - 12.8 u = 49 - 28.20
1.3 u = 20.80
1 u = 20.80 ÷ 1.3 = 16
Number of gifts that she bought for her relatives
= 1 u
= 16
Answer(s): 16
