Jack, Warren and Albert had the same number of balls. Albert gave 0.6 of his balls to Warren. Then Warren gave 0.25 of his balls to Jack. Finally, after Warren gave 30 balls to Albert, he had the same number of balls as Albert. How many balls did Albert have at first?
| |
Jack |
Warren |
Albert |
| Before |
1 u |
1 u |
1 u |
| Change 1 |
|
+ 0.6 u |
- 0.6 u |
| After 1 |
1 u |
1.6 u |
0.4 u |
| Change 2 |
+ 0.4 u |
- 0.4 u |
|
| After 2 |
1.4 u |
1.2 u |
0.4 u |
| Change 3 |
|
- 30 |
+ 30 |
| After 3 |
1.4 u |
1.2 u - 30 |
0.4 u + 30 |
Number of balls that Warren gave to Jack
= 0.25 x 1.6 u
= 0.4 u
The number of balls that Warren and Albert had in the end is the same.
1.2 u - 30 = 0.4 u + 30
1.2 u - 0.4 u = 30 + 30
0.8 u = 60
1 u = 60 ÷ 0.8 = 75
Number of balls that Albert had at first
= 1 u
= 75
Answer(s): 75
