Owen, Rael and Pierre had the same number of balls. Pierre gave 0.5 of his balls to Rael. Then Rael gave 0.25 of his balls to Owen. Finally, after Rael gave 20 balls to Pierre, he had the same number of balls as Pierre. How many balls did Pierre have at first?
| |
Owen |
Rael |
Pierre |
| 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 Rael gave to Owen
= 0.25 x 1.5 u
= 0.375 u
The number of balls that Rael and Pierre 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 Pierre had at first
= 1 u
= 64
Answer(s): 64
