Henry had 3 times as many green markers as grey markers. After giving away 8 green markers and buying another 12 grey markers, he had an equal number of green and grey markers. How many green markers did Henry have at first?
| |
Green markers |
Grey markers |
| Before |
3 u |
1 u |
| Change |
- 8 |
+ 12 |
| After |
3 u - 8 |
1 u + 12 |
The number of green and grey markers is the same in the end.
3 u - 8 = 1 u + 12
3 u - 1 u = 12 + 8
2 u = 8 + 12
2 u = 20
1 u = 20 ÷ 2 = 10
Number of green markers that Henry had at first
= 3 u
= 3 x 10
= 30
Answer(s): 30
