Zane, Seth and Vincent had the same number of balls. Vincent gave 0.5 of his balls to Seth. Then Seth gave 0.25 of his balls to Zane. Finally, after Seth gave 20 balls to Vincent, he had the same number of balls as Vincent. How many balls did Vincent have at first?
| |
Zane |
Seth |
Vincent |
| Before |
1 u |
1 u |
1 u |
| Change 1 |
|
+ 0.5 u |
- 0.5 u |
| After 1 |
1 u |
1.5 u |
0.5 u |
| Change 2 |
+ 0.375 u |
- 0.375 u |
|
| After 2 |
1.375 u |
1.125 u |
0.5 u |
| Change 3 |
|
- 20 |
+ 20 |
| After 3 |
1.375 u |
1.125 u - 20 |
0.5 u + 20 |
Number of balls that Seth gave to Zane
= 0.25 x 1.5 u
= 0.375 u
The number of balls that Seth and Vincent had in the end is the same.
1.125 u - 20 = 0.5 u + 20
1.125 u - 0.5 u = 20 + 20
0.625 u = 40
1 u = 40 ÷ 0.625 = 64
Number of balls that Vincent had at first
= 1 u
= 64
Answer(s): 64
