Last week, Sean had a total of 114 gold and red pencils. Two weeks later, he sold
45 of all the gold pencils and bought another 12 red pencils. Now he has the same number of gold and red pencils. How many pencils does he have in the end?
| |
Gold |
Red |
Total |
| Before |
5 u |
1 u - 12 |
6 u - 12 |
| Change |
- 4 u |
+ 12 |
|
| After |
1 u |
1 u |
|
Comparing the gold
and red pencils in the end |
1 |
1 |
|
Total number of pencils at first
= 5 u + 1 u - 12
= 6 u - 12
6 u - 12 = 114
6 u = 114 + 12
6 u = 126
1 u = 126 ÷ 6 = 21
Number of pencils that he has in the end
= 1 u + 1 u
= 2 u
= 2 x 21
= 42
Answer(s): 42
