Lynn, Usha and Sabrina each had some beads and decided to play a game with their beads. In round 1, Lynn lost
12 of her beads to Usha. In round 2, Usha lost
12 of her total number of beads to Sabrina. In round 3, Sabrina lost
12 of her total number of beads to Lynn. In the end, Lynn, Usha and Sabrina had 134, 105 and 75 beads respectively. How many beads did Usha have at first?
|
Lynn |
Usha |
Sabrina |
Before 1 |
2 b |
151 |
|
Change 1 |
- 1 b |
+ 1 b |
|
After 1 |
1 b |
210 |
|
Before 2 |
59 |
2 u |
|
Change 2 |
|
- 1 u |
+1 |
After 2 |
|
1 u |
150 |
Before 3 |
|
|
2 p |
Change 3 |
+ 1 p |
|
- 1 p |
After 3 |
|
|
1 p |
Comparing Lynn, Usha and Sabrina in the end |
134 |
105 |
75 |
Working backwards.
1 p = 75
At the start of Round 3:
Number of beads that Sabrina had
= 2 p
= 2 x 75
= 150
At the start of Round 2:
Number of beads that Lynn had
= 134 - 1 p
= 134 - 75
= 59
At the end of Round 3:
Number of beads that Usha had = 105
1 u = 105
At the end of Round 1:
Number of beads that Usha had
= 2 u
= 2 x 105
= 210
1 b = 59
At the end of Round 1:
Number of beads that Lynn had = 59
At the start of Round 1:
Number of beads that Usha had
= 210 - 1 b
= 210 - 59
= 151
Answer(s): 151