Betty bought some gifts for her cousins at an average price of $13.40. If Betty decided to buy a pen which cost $19 for her father and a bag which cost $33 for her mother, the average price of the gifts would become $14.10. How many gifts did Betty buy for her cousins?
| |
Cousins |
Cousins and parents |
| Number |
1 u |
1 u + 2 |
| Value |
13.40 |
14.10 |
| Total Value |
13.40 u |
14.10 u + 28.20 |
Number of gifts that Betty bought for her cousins = 1 u
Amount that Betty spent on the gifts for her cousins
= 1 u x 13.40
= 13.40 u
Amount that $(Lizy) spent if she bought for her parents
= 19 + 33
= $52
Total number of items bought if she bought for her parents and her cousins
= 1 u + 1 + 1
= 1 u + 2
Total amount that she spent if she bought for her parents and her cousins
= 14.10(1 u + 2)
= 14.10 u + 28.20
13.4 u + 52 = 14.10 u + 28.20
14.10 u - 13.4 u = 52 - 28.20
0.7 u = 23.80
1 u = 23.80 ÷ 0.7 = 34
Number of gifts that she bought for her cousins
= 1 u
= 34
Answer(s): 34
