Last week, Japheth had a total of 243 grey and silver pens. Two weeks later, he sold
34 of all the grey pens and bought another 12 silver pens. Now he has the same number of grey and silver pens. How many pens does he have in the end?
| |
Grey |
Silver |
Total |
| Before |
4 u |
1 u - 12 |
5 u - 12 |
| Change |
- 3 u |
+ 12 |
|
| After |
1 u |
1 u |
|
Comparing the grey
and silver pens in the end |
1 |
1 |
|
Total number of pens at first
= 4 u + 1 u - 12
= 5 u - 12
5 u - 12 = 243
5 u = 243 + 12
5 u = 255
1 u = 255 ÷ 5 = 51
Number of pens that he has in the end
= 1 u + 1 u
= 2 u
= 2 x 51
= 102
Answer(s): 102
