Last week, Charlie had a total of 47 red and grey staplers. Two weeks later, he sold
34 of all the red staplers and bought another 28 grey staplers. Now he has the same number of red and grey staplers. How many staplers does he have in the end?
| |
Red |
Grey |
Total |
| Before |
4 u |
1 u - 28 |
5 u - 28 |
| Change |
- 3 u |
+ 28 |
|
| After |
1 u |
1 u |
|
Comparing the red
and grey staplers in the end |
1 |
1 |
|
Total number of staplers at first
= 4 u + 1 u - 28
= 5 u - 28
5 u - 28 = 47
5 u = 47 + 28
5 u = 75
1 u = 75 ÷ 5 = 15
Number of staplers that he has in the end
= 1 u + 1 u
= 2 u
= 2 x 15
= 30
Answer(s): 30
