Isaiah bought 61 pens and George bought 78 pens. After George used
37 times as many pens as Isaiah, he was left with twice as many pens as Isaiah. How many pens did each of them have in the end?
- Isaiah
- George
| |
Make p the same.
(1)x2 = (3) |
Isaiah
(1) |
George
(2) |
| Before |
122 |
61 |
78 |
| Change |
- 14 u |
- 7 u |
- 3 u |
| After |
2 p |
1 p |
2 p |
(a)
61 - 7 u = 1 p --- (1)
78 - 3 u =
2 p --- (2)
(1)
x2
122 - 14 u =
2 p --- (3)
(3) = (2)
78 - 3 u = 122 - 14 u
14 u - 3 u = 122 - 78
11 u = 44
1 u = 44 ÷ 11 = 4
Number of pens that Isaiah had in the end
= 61 - 7 u
= 61 - 7 x 4
= 61 - 28
= 33
(b)
1 p = 33
Number of pens that George had in the end
= 2 p
= 2 x 33
= 66
Answer(s): (a) 33; (b) 66
