Pierre had 4 times as many pink pencils as red pencils. After giving away 8 pink pencils and buying another 19 red pencils, he had an equal number of pink and red pencils. How many pink pencils did Pierre have at first?
| |
Pink pencils |
Red pencils |
| Before |
4 u |
1 u |
| Change |
- 8 |
+ 19 |
| After |
4 u - 8 |
1 u + 19 |
The number of pink and red pencils is the same in the end.
4 u - 8 = 1 u + 19
4 u - 1 u = 19 + 8
3 u = 8 + 19
3 u = 27
1 u = 27 ÷ 3 = 9
Number of pink pencils that Pierre had at first
= 4 u
= 4 x 9
= 36
Answer(s): 36
