Billy had 5 times as many pink pencils as white pencils. After giving away 9 pink pencils and buying another 39 white pencils, he had an equal number of pink and white pencils. How many pink pencils did Billy have at first?
| |
Pink pencils |
White pencils |
| Before |
5 u |
1 u |
| Change |
- 9 |
+ 39 |
| After |
5 u - 9 |
1 u + 39 |
The number of pink and white pencils is the same in the end.
5 u - 9 = 1 u + 39
5 u - 1 u = 39 + 9
4 u = 9 + 39
4 u = 48
1 u = 48 ÷ 4 = 12
Number of pink pencils that Billy had at first
= 5 u
= 5 x 12
= 60
Answer(s): 60
