Last week, Riordan had a total of 79 yellow and blue pencils. Two weeks later, he sold
34 of all the yellow pencils and bought another 16 blue pencils. Now he has the same number of yellow and blue pencils. How many pencils does he have in the end?
| |
Yellow |
Blue |
Total |
| Before |
4 u |
1 u - 16 |
5 u - 16 |
| Change |
- 3 u |
+ 16 |
|
| After |
1 u |
1 u |
|
Comparing the yellow
and blue pencils in the end |
1 |
1 |
|
Total number of pencils at first
= 4 u + 1 u - 16
= 5 u - 16
5 u - 16 = 79
5 u = 79 + 16
5 u = 95
1 u = 95 ÷ 5 = 19
Number of pencils that he has in the end
= 1 u + 1 u
= 2 u
= 2 x 19
= 38
Answer(s): 38
