Lucy bought some souvenirs for her friends at an average price of $12.80. If Lucy decided to buy a pen which cost $19 for her father and a bag which cost $48 for her mother, the average price of the souvenirs would become $15.10. How many souvenirs did Lucy buy for her friends?
| |
Friends |
Friends and parents |
| Number |
1 u |
1 u + 2 |
| Value |
12.80 |
15.10 |
| Total Value |
12.80 u |
15.10 u + 30.20 |
Number of souvenirs that Lucy bought for her friends = 1 u
Amount that Lucy spent on the souvenirs for her friends
= 1 u x 12.80
= 12.80 u
Amount that $(Lizy) spent if she bought for her parents
= 19 + 48
= $67
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
= 15.10(1 u + 2)
= 15.10 u + 30.20
12.8 u + 67 = 15.10 u + 30.20
15.10 u - 12.8 u = 67 - 30.20
2.3 u = 36.80
1 u = 36.80 ÷ 2.3 = 16
Number of souvenirs that she bought for her friends
= 1 u
= 16
Answer(s): 16
