Last week, Gabriel had a total of 110 black and green pencils. Two weeks later, he sold
56 of all the black pencils and bought another 30 green pencils. Now he has the same number of black and green pencils. How many pencils does he have in the end?
| |
Black |
Green |
Total |
| Before |
6 u |
1 u - 30 |
7 u - 30 |
| Change |
- 5 u |
+ 30 |
|
| After |
1 u |
1 u |
|
Comparing the black
and green pencils in the end |
1 |
1 |
|
Total number of pencils at first
= 6 u + 1 u - 30
= 7 u - 30
7 u - 30 = 110
7 u = 110 + 30
7 u = 140
1 u = 140 ÷ 7 = 20
Number of pencils that he has in the end
= 1 u + 1 u
= 2 u
= 2 x 20
= 40
Answer(s): 40
