Henry, Vaidev and Ryan had 168 pencils. After Henry used 15 pencils and Vaidev used
18 of her pencils, Henry had four times as many pencils left as Vaidev. Ryan bought another 18 pencils, he had thrice the number of pencils Vaidev had left. How many pencils did Ryan have at first?
| |
Henry |
Vaidev |
Ryan |
Total |
| Before |
28 u + 15 |
8 u |
21 u - 18 |
168 |
| Change |
- 15 |
- 1 u |
+ 18 |
|
| After |
28 u |
7 u |
21 u |
|
Comparing Henry
and Vaidev in the end |
4 |
1 |
|
|
Comparing Ryan
and Vaidev in the end |
|
1 |
3 |
|
Number of pencils that Henry had in the end
= 4 x 7 u
= 28 u
Number of pencils that Ryan had in the end
= 3 x 7 u
= 21 u
Total number of pencils at first
= 28 u + 15 + 8 u + 21 u - 18
= 57 u - 3
57 u - 3 = 168
57 u = 168 + 3
57 u = 171
1 u = 171 ÷ 57 = 3
Number of pencils that Ryan had at first
= 21 u - 18
= 21 x 3 - 18
= 63 - 18
= 45
Answer(s): 45
