Cathy and Tina had the same number of pens. After Cathy had given away 64 pens, Tina had 9 times as many pens as Cathy. How many pens did each of them have at first?
| |
Cathy |
Tina |
| Before |
1 u + 64 |
9 u |
| Change |
- 64 |
|
| After |
1 u |
9 u |
Number of pens that Tina had remains unchanged.
Number of pens that Cathy and Tina had at first is equal.
9 u = 1 u + 64
9 u - 1 u = 64
8 u = 64
1 u = 64 ÷ 8= 8
Number of pens that each of them had at first
= 1 u + 64
= 8 + 64
= 72
Answer(s): 72
