Last week, Brandon had a total of 235 silver and black pens. Two weeks later, he sold
45 of all the silver pens and bought another 11 black pens. Now he has the same number of silver and black pens. How many pens does he have in the end?
| |
Silver |
Black |
Total |
| Before |
5 u |
1 u - 11 |
6 u - 11 |
| Change |
- 4 u |
+ 11 |
|
| After |
1 u |
1 u |
|
Comparing the silver
and black pens in the end |
1 |
1 |
|
Total number of pens at first
= 5 u + 1 u - 11
= 6 u - 11
6 u - 11 = 235
6 u = 235 + 11
6 u = 246
1 u = 246 ÷ 6 = 41
Number of pens that he has in the end
= 1 u + 1 u
= 2 u
= 2 x 41
= 82
Answer(s): 82
