Last week, Paul had a total of 138 silver and brown notebooks. Two weeks later, he sold
23 of all the silver notebooks and bought another 2 brown notebooks. Now he has the same number of silver and brown notebooks. How many notebooks does he have in the end?
| |
Silver |
Brown |
Total |
| Before |
3 u |
1 u - 2 |
4 u - 2 |
| Change |
- 2 u |
+ 2 |
|
| After |
1 u |
1 u |
|
Comparing the silver
and brown notebooks in the end |
1 |
1 |
|
Total number of notebooks at first
= 3 u + 1 u - 2
= 4 u - 2
4 u - 2 = 138
4 u = 138 + 2
4 u = 140
1 u = 140 ÷ 4 = 35
Number of notebooks that he has in the end
= 1 u + 1 u
= 2 u
= 2 x 35
= 70
Answer(s): 70
