Gwen, Wendy and Usha each had some beads and decided to play a game with their beads. In round 1, Gwen lost
13 of her beads to Wendy. In round 2, Wendy lost
13 of her total number of beads to Usha. In round 3, Usha lost
13 of her total number of beads to Gwen. In the end, Gwen, Wendy and Usha had 130, 100 and 56 beads respectively. How many beads did Wendy have at first?
|
Gwen |
Wendy |
Usha |
|
|
99 |
|
Before 1 |
3 b |
|
|
Change 1 |
- 1 b |
+ 1 b |
|
After 1 |
2 b |
150 |
|
Before 2 |
102 |
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 Gwen, Wendy and Usha in the end |
130 |
100 |
56 |
Working backwards.
2 p = 56
1 p = 56 ÷ 2 = 28
At the start of Round 3:
Number of beads that Usha had
= 3 p
= 3 x 28
= 84
2 u = 100
1 u = 100 ÷ 2 = 50
At the start of Round 2:
Number of beads that Wendy had
= 3 u
= 3 x 50
= 150
At the start of Round 2:
Number of beads that Gwen had
= 130 - 28
= 102
2 b = 102
1 b = 102 ÷ 2 = 51
At the start of Round 1:
Number of beads that Wendy had
= 150 - 1 b
= 150 - 51
= 99
Answer(s): 99