Kimberly, Gillian and Shannon each had some balls and decided to play a game with their balls. In round 1, Kimberly lost
13 of her balls to Gillian. In round 2, Gillian lost
13 of her total number of balls to Shannon. In round 3, Shannon lost
13 of her total number of balls to Kimberly. In the end, Kimberly, Gillian and Shannon had 120, 94 and 56 balls respectively. How many balls did Gillian have at first?
|
Kimberly |
Gillian |
Shannon |
|
|
95 |
|
Before 1 |
3 b |
|
|
Change 1 |
- 1 b |
+ 1 b |
|
After 1 |
2 b |
141 |
|
Before 2 |
92 |
3 u |
|
Change 2 |
|
- 1 u |
+ 1 u |
After 2 |
|
2 u |
84 |
Before 3 |
|
|
3 p |
Change 3 |
+ 1 p |
|
- 1 p |
After 3 |
|
|
2 p |
Comparing Kimberly, Gillian and Shannon in the end |
120 |
94 |
56 |
Working backwards.
2 p = 56
1 p = 56 ÷ 2 = 28
At the start of Round 3:
Number of balls that Shannon had
= 3 p
= 3 x 28
= 84
2 u = 94
1 u = 94 ÷ 2 = 47
At the start of Round 2:
Number of balls that Gillian had
= 3 u
= 3 x 47
= 141
At the start of Round 2:
Number of balls that Kimberly had
= 120 - 28
= 92
2 b = 92
1 b = 92 ÷ 2 = 46
At the start of Round 1:
Number of balls that Gillian had
= 141 - 1 b
= 141 - 46
= 95
Answer(s): 95