Wendy, Penelope and Jade each had some beads and decided to play a game with their beads. In round 1, Wendy lost
12 of her beads to Penelope. In round 2, Penelope lost
12 of her total number of beads to Jade. In round 3, Jade lost
12 of her total number of beads to Wendy. In the end, Wendy, Penelope and Jade had 137, 81 and 60 beads respectively. How many beads did Penelope have at first?
|
Wendy |
Penelope |
Jade |
Before 1 |
2 b |
85 |
|
Change 1 |
- 1 b |
+ 1 b |
|
After 1 |
1 b |
162 |
|
Before 2 |
77 |
2 u |
|
Change 2 |
|
- 1 u |
+1 |
After 2 |
|
1 u |
120 |
Before 3 |
|
|
2 p |
Change 3 |
+ 1 p |
|
- 1 p |
After 3 |
|
|
1 p |
Comparing Wendy, Penelope and Jade in the end |
137 |
81 |
60 |
Working backwards.
1 p = 60
At the start of Round 3:
Number of beads that Jade had
= 2 p
= 2 x 60
= 120
At the start of Round 2:
Number of beads that Wendy had
= 137 - 1 p
= 137 - 60
= 77
At the end of Round 3:
Number of beads that Penelope had = 81
1 u = 81
At the end of Round 1:
Number of beads that Penelope had
= 2 u
= 2 x 81
= 162
1 b = 77
At the end of Round 1:
Number of beads that Wendy had = 77
At the start of Round 1:
Number of beads that Penelope had
= 162 - 1 b
= 162 - 77
= 85
Answer(s): 85