Dana bought some souvenirs for her friends at an average price of $10.70. If Dana decided to buy a pen which cost $13 for her father and a bag which cost $42 for her mother, the average price of the souvenirs would become $14.90. How many souvenirs did Dana buy for her friends?
| |
Friends |
Friends and parents |
| Number |
1 u |
1 u + 2 |
| Value |
10.70 |
14.90 |
| Total Value |
10.70 u |
14.90 u + 29.80 |
Number of souvenirs that Dana bought for her friends = 1 u
Amount that Dana spent on the souvenirs for her friends
= 1 u x 10.70
= 10.70 u
Amount that $(Lizy) spent if she bought for her parents
= 13 + 42
= $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
= 14.90(1 u + 2)
= 14.90 u + 29.80
10.7 u + 55 = 14.90 u + 29.80
14.90 u - 10.7 u = 55 - 29.80
4.2 u = 25.20
1 u = 25.20 ÷ 4.2 = 6
Number of souvenirs that she bought for her friends
= 1 u
= 6
Answer(s): 6
