Gabby bought some gifts for her friends at an average price of $10.70. If Gabby decided to buy a pen which cost $12 for her father and a bag which cost $43 for her mother, the average price of the gifts would become $16.30. How many gifts did Gabby buy for her friends?
| |
Friends |
Friends and parents |
| Number |
1 u |
1 u + 2 |
| Value |
10.70 |
16.30 |
| Total Value |
10.70 u |
16.30 u + 32.60 |
Number of gifts that Gabby bought for her friends = 1 u
Amount that Gabby spent on the gifts for her friends
= 1 u x 10.70
= 10.70 u
Amount that $(Lizy) spent if she bought for her parents
= 12 + 43
= $55
Total number of items bought if she bought for her parents and her friends
= 1 u + 1 + 1
= 1 u + 2
Total amount that she spent if she bought for her parents and her friends
= 16.30(1 u + 2)
= 16.30 u + 32.60
10.7 u + 55 = 16.30 u + 32.60
16.30 u - 10.7 u = 55 - 32.60
5.6 u = 22.40
1 u = 22.40 ÷ 5.6 = 4
Number of gifts that she bought for her friends
= 1 u
= 4
Answer(s): 4
