Audrey bought 80 pens and Tommy bought 96 pens. After Tommy used
35 times as many pens as Audrey, he was left with thrice as many pens as Audrey. How many pens did each of them have in the end?
- Audrey
- Tommy
| |
Make p the same.
(1)x3 = (3) |
Audrey
(1) |
Tommy
(2) |
| Before |
240 |
80 |
96 |
| Change |
- 15 u |
- 5 u |
- 3 u |
| After |
3 p |
1 p |
3 p |
(a)
80 - 5 u = 1 p --- (1)
96 - 3 u =
3 p --- (2)
(1)
x3
240 - 15 u =
3 p --- (3)
(3) = (2)
96 - 3 u = 240 - 15 u
15 u - 3 u = 240 - 96
12 u = 144
1 u = 144 ÷ 12 = 12
Number of pens that Audrey had in the end
= 80 - 5 u
= 80 - 5 x 12
= 80 - 60
= 20
(b)
1 p = 20
Number of pens that Tommy had in the end
= 3 p
= 3 x 20
= 60
Answer(s): (a) 20; (b) 60
