Kimberly, Gwen and Tiffany each had some beads and decided to play a game with their beads. In round 1, Kimberly lost
13 of her beads to Gwen. In round 2, Gwen lost
13 of her total number of beads to Tiffany. In round 3, Tiffany lost
13 of her total number of beads to Kimberly. In the end, Kimberly, Gwen and Tiffany had 126, 86 and 80 beads respectively. How many beads did Gwen have at first?
|
Kimberly |
Gwen |
Tiffany |
|
|
86 |
|
Before 1 |
3 b |
|
|
Change 1 |
- 1 b |
+ 1 b |
|
After 1 |
2 b |
129 |
|
Before 2 |
86 |
3 u |
|
Change 2 |
|
- 1 u |
+ 1 u |
After 2 |
|
2 u |
120 |
Before 3 |
|
|
3 p |
Change 3 |
+ 1 p |
|
- 1 p |
After 3 |
|
|
2 p |
Comparing Kimberly, Gwen and Tiffany in the end |
126 |
86 |
80 |
Working backwards.
2 p = 80
1 p = 80 ÷ 2 = 40
At the start of Round 3:
Number of beads that Tiffany had
= 3 p
= 3 x 40
= 120
2 u = 86
1 u = 86 ÷ 2 = 43
At the start of Round 2:
Number of beads that Gwen had
= 3 u
= 3 x 43
= 129
At the start of Round 2:
Number of beads that Kimberly had
= 126 - 40
= 86
2 b = 86
1 b = 86 ÷ 2 = 43
At the start of Round 1:
Number of beads that Gwen had
= 129 - 1 b
= 129 - 43
= 86
Answer(s): 86