Sabrina bought some presents for her cousins at an average price of $10.80. If Sabrina decided to buy a pen which cost $12 for her father and a bag which cost $33 for her mother, the average price of the presents would become $14.70. How many presents did Sabrina buy for her cousins?
| |
Cousins |
Cousins and parents |
| Number |
1 u |
1 u + 2 |
| Value |
10.80 |
14.70 |
| Total Value |
10.80 u |
14.70 u + 29.40 |
Number of presents that Sabrina bought for her cousins = 1 u
Amount that Sabrina spent on the presents for her cousins
= 1 u x 10.80
= 10.80 u
Amount that $(Lizy) spent if she bought for her parents
= 12 + 33
= $45
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
= 14.70(1 u + 2)
= 14.70 u + 29.40
10.8 u + 45 = 14.70 u + 29.40
14.70 u - 10.8 u = 45 - 29.40
3.9 u = 15.60
1 u = 15.60 ÷ 3.9 = 4
Number of presents that she bought for her cousins
= 1 u
= 4
Answer(s): 4
