Risa bought 38 staplers and Tim bought 78 staplers. After Tim used
35 times as many staplers as Risa, he was left with thrice as many staplers as Risa. How many staplers did each of them have in the end?
- Risa
- Tim
| |
Make p the same.
(1)x3 = (3) |
Risa
(1) |
Tim
(2) |
| Before |
114 |
38 |
78 |
| Change |
- 15 u |
- 5 u |
- 3 u |
| After |
3 p |
1 p |
3 p |
(a)
38 - 5 u = 1 p --- (1)
78 - 3 u =
3 p --- (2)
(1)
x3
114 - 15 u =
3 p --- (3)
(3) = (2)
78 - 3 u = 114 - 15 u
15 u - 3 u = 114 - 78
12 u = 36
1 u = 36 ÷ 12 = 3
Number of staplers that Risa had in the end
= 38 - 5 u
= 38 - 5 x 3
= 38 - 15
= 23
(b)
1 p = 23
Number of staplers that Tim had in the end
= 3 p
= 3 x 23
= 69
Answer(s): (a) 23; (b) 69
