Ryan and Charlie had 85 files together. Charlie had 5 less files than Ryan. Both of them sold some of their files. Charlie sold 20% more files than what Ryan sold. In the end, Charlie had half as many files left as Ryan. How many files had Charlie left?
| |
Ryan
(1) |
Charlie
(2) |
Make p the same
(2)x2 = (3) |
Comparing Ryan
and Charlie at first |
5 more |
|
|
| Before |
45 |
40 |
80 |
| Change |
- 5 u |
- 6 u |
- 12 u |
| After |
2 p |
1 p |
2 p |
Number of files that Charlie had at first
= (85 - 5) ÷ 2
= 80 ÷ 2
= 40
Number of files that Ryan had at first
= 40 + 5
= 45
Number of files that Charlie sold in percent
= 100% + 20%
= 120%
120% =
120100 =
65 Make p the same.
(1) = (3)
45 - 5 u = 80 - 12 u
12 u - 5 u = 80 - 45
7 u = 35
1 u = 35 ÷ 7 = 5
Number of files that Charlie had left
= 40 - 6 u
= 40 - 6 x 5
= 40 - 30
= 10
Answer(s): 10
