Liam had 4 times as many brown pencils as blue pencils. After giving away 7 brown pencils and buying another 8 blue pencils, he had an equal number of brown and blue pencils. How many brown pencils did Liam have at first?
| |
Brown pencils |
Blue pencils |
| Before |
4 u |
1 u |
| Change |
- 7 |
+ 8 |
| After |
4 u - 7 |
1 u + 8 |
The number of brown and blue pencils is the same in the end.
4 u - 7 = 1 u + 8
4 u - 1 u = 8 + 7
3 u = 7 + 8
3 u = 15
1 u = 15 ÷ 3 = 5
Number of brown pencils that Liam had at first
= 4 u
= 4 x 5
= 20
Answer(s): 20
