Last week, Sean had a total of 51 yellow and purple notebooks. Two weeks later, he sold
23 of all the yellow notebooks and bought another 25 purple notebooks. Now he has the same number of yellow and purple notebooks. How many notebooks does he have in the end?
| |
Yellow |
Purple |
Total |
| Before |
3 u |
1 u - 25 |
4 u - 25 |
| Change |
- 2 u |
+ 25 |
|
| After |
1 u |
1 u |
|
Comparing the yellow
and purple notebooks in the end |
1 |
1 |
|
Total number of notebooks at first
= 3 u + 1 u - 25
= 4 u - 25
4 u - 25 = 51
4 u = 51 + 25
4 u = 76
1 u = 76 ÷ 4 = 19
Number of notebooks that he has in the end
= 1 u + 1 u
= 2 u
= 2 x 19
= 38
Answer(s): 38
