Last week, Neave had a total of 252 red and purple notebooks. Two weeks later, he sold
45 of all the red notebooks and bought another 18 purple notebooks. Now he has the same number of red and purple notebooks. How many notebooks does he have in the end?
| |
Red |
Purple |
Total |
| Before |
5 u |
1 u - 18 |
6 u - 18 |
| Change |
- 4 u |
+ 18 |
|
| After |
1 u |
1 u |
|
Comparing the red
and purple notebooks in the end |
1 |
1 |
|
Total number of notebooks at first
= 5 u + 1 u - 18
= 6 u - 18
6 u - 18 = 252
6 u = 252 + 18
6 u = 270
1 u = 270 ÷ 6 = 45
Number of notebooks that he has in the end
= 1 u + 1 u
= 2 u
= 2 x 45
= 90
Answer(s): 90
