Ethan had 5 times as many purple pens as gold pens. After giving away 4 purple pens and buying another 36 gold pens, he had an equal number of purple and gold pens. How many purple pens did Ethan have at first?
| |
Purple pens |
Gold pens |
| Before |
5 u |
1 u |
| Change |
- 4 |
+ 36 |
| After |
5 u - 4 |
1 u + 36 |
The number of purple and gold pens is the same in the end.
5 u - 4 = 1 u + 36
5 u - 1 u = 36 + 4
4 u = 4 + 36
4 u = 40
1 u = 40 ÷ 4 = 10
Number of purple pens that Ethan had at first
= 5 u
= 5 x 10
= 50
Answer(s): 50
