Cody and Pierre had 40 files together. Pierre had 4 less files than Cody. Both of them sold some of their files. Pierre sold 20% more files than what Cody sold. In the end, Pierre had half as many files left as Cody. How many files had Pierre left?
| |
Cody
(1) |
Pierre
(2) |
Make p the same
(2)x2 = (3) |
Comparing Cody
and Pierre at first |
4 more |
|
|
| Before |
22 |
18 |
36 |
| Change |
- 5 u |
- 6 u |
- 12 u |
| After |
2 p |
1 p |
2 p |
Number of files that Pierre had at first
= (40 - 4) ÷ 2
= 36 ÷ 2
= 18
Number of files that Cody had at first
= 18 + 4
= 22
Number of files that Pierre sold in percent
= 100% + 20%
= 120%
120% =
120100 =
65 Make p the same.
(1) = (3)
22 - 5 u = 36 - 12 u
12 u - 5 u = 36 - 22
7 u = 14
1 u = 14 ÷ 7 = 2
Number of files that Pierre had left
= 18 - 6 u
= 18 - 6 x 2
= 18 - 12
= 6
Answer(s): 6
