Luke had 3 times as many grey pencils as pink pencils. After giving away 8 grey pencils and buying another 2 pink pencils, he had an equal number of grey and pink pencils. How many grey pencils did Luke have at first?
| |
Grey pencils |
Pink pencils |
| Before |
3 u |
1 u |
| Change |
- 8 |
+ 2 |
| After |
3 u - 8 |
1 u + 2 |
The number of grey and pink pencils is the same in the end.
3 u - 8 = 1 u + 2
3 u - 1 u = 2 + 8
2 u = 8 + 2
2 u = 10
1 u = 10 ÷ 2 = 5
Number of grey pencils that Luke had at first
= 3 u
= 3 x 5
= 15
Answer(s): 15
