Last week, Tom had a total of 236 white and purple notebooks. Two weeks later, he sold
34 of all the white notebooks and 21 purple notebooks. Now he has the same number of white and purple notebooks. How many notebooks does he have in the end?
| |
White |
Purple |
Total |
| Before |
4 u |
1 u + 21 |
5 u + 21 |
| Change |
- 3 u |
- 21 |
|
| After |
1 u |
1 u |
|
Comparing the white
and purple notebooks in the end |
1 |
1 |
|
Total number of notebooks at first
= 4 u + 1 u + 21
= 5 u + 21
5 u + 21 = 236
5 u = 236 - 21
5 u = 215
1 u = 215 ÷ 5 = 43
Number of notebooks that he has in the end
= 1 u + 1 u
= 2 u
= 2 x 43
= 86
Answer(s): 86
