Ethan and Oliver had 60 files together. Ethan had 8 more files than Oliver. Both of them sold some of their files. Oliver sold 20% less files than what Ethan sold. In the end, Oliver had half as many files left as Ethan. How many files had Ethan left?
| |
Ethan
(1) |
Oliver
(2) |
Make p the same
(2)x2 = (3) |
Comparing Ethan
and Oliver at first |
8 more |
|
|
| Before |
34 |
26 |
52 |
| Change |
- 5 u |
- 4 u |
- 8 u |
| After |
2 p |
1 p |
2 p |
Number of files that Oliver had at first
= (60 - 8) ÷ 2
= 52 ÷ 2
= 26
Number of files that Ethan had at first
= 26 + 8
= 34
Number of files that Oliver sold in percent
= 100% - 20%
= 80%
80% =
80100 =
45 Make p the same.
(1) = (3)
34 - 5 u = 52 - 8 u
8 u - 5 u = 52 - 34
3 u = 18
1 u = 18 ÷ 3 = 6
Number of files that Ethan had left
= 34 - 5 u
= 34 - 5 x 6
= 34 - 30
= 4
Answer(s): 4
