Kimberly, Jaslyn and Risa each had some beads and decided to play a game with their beads. In round 1, Kimberly lost
12 of her beads to Jaslyn. In round 2, Jaslyn lost
12 of her total number of beads to Risa. In round 3, Risa lost
12 of her total number of beads to Kimberly. In the end, Kimberly, Jaslyn and Risa had 129, 103 and 55 beads respectively. How many beads did Jaslyn have at first?
|
Kimberly |
Jaslyn |
Risa |
Before 1 |
2 b |
132 |
|
Change 1 |
- 1 b |
+ 1 b |
|
After 1 |
1 b |
206 |
|
Before 2 |
74 |
2 u |
|
Change 2 |
|
- 1 u |
+1 |
After 2 |
|
1 u |
110 |
Before 3 |
|
|
2 p |
Change 3 |
+ 1 p |
|
- 1 p |
After 3 |
|
|
1 p |
Comparing Kimberly, Jaslyn and Risa in the end |
129 |
103 |
55 |
Working backwards.
1 p = 55
At the start of Round 3:
Number of beads that Risa had
= 2 p
= 2 x 55
= 110
At the start of Round 2:
Number of beads that Kimberly had
= 129 - 1 p
= 129 - 55
= 74
At the end of Round 3:
Number of beads that Jaslyn had = 103
1 u = 103
At the end of Round 1:
Number of beads that Jaslyn had
= 2 u
= 2 x 103
= 206
1 b = 74
At the end of Round 1:
Number of beads that Kimberly had = 74
At the start of Round 1:
Number of beads that Jaslyn had
= 206 - 1 b
= 206 - 74
= 132
Answer(s): 132