Last week, Perry had a total of 122 blue and gold notebooks. Two weeks later, he sold
56 of all the blue notebooks and bought another 25 gold notebooks. Now he has the same number of blue and gold notebooks. How many notebooks does he have in the end?
| |
Blue |
Gold |
Total |
| Before |
6 u |
1 u - 25 |
7 u - 25 |
| Change |
- 5 u |
+ 25 |
|
| After |
1 u |
1 u |
|
Comparing the blue
and gold notebooks in the end |
1 |
1 |
|
Total number of notebooks at first
= 6 u + 1 u - 25
= 7 u - 25
7 u - 25 = 122
7 u = 122 + 25
7 u = 147
1 u = 147 ÷ 7 = 21
Number of notebooks that he has in the end
= 1 u + 1 u
= 2 u
= 2 x 21
= 42
Answer(s): 42
