Lily bought 80 files and Mark bought 88 files. After Mark used
27 times as many files as Lily, he was left with thrice as many files as Lily. How many files did each of them have in the end?
- Lily
- Mark
| |
Make p the same.
(1)x3 = (3) |
Lily
(1) |
Mark
(2) |
| Before |
240 |
80 |
88 |
| Change |
- 21 u |
- 7 u |
- 2 u |
| After |
3 p |
1 p |
3 p |
(a)
80 - 7 u = 1 p --- (1)
88 - 2 u =
3 p --- (2)
(1)
x3
240 - 21 u =
3 p --- (3)
(3) = (2)
88 - 2 u = 240 - 21 u
21 u - 2 u = 240 - 88
19 u = 152
1 u = 152 ÷ 19 = 8
Number of files that Lily had in the end
= 80 - 7 u
= 80 - 7 x 8
= 80 - 56
= 24
(b)
1 p = 24
Number of files that Mark had in the end
= 3 p
= 3 x 24
= 72
Answer(s): (a) 24; (b) 72
