Tammy, Usha and Wendy each had some balls and decided to play a game with their balls. In round 1, Tammy lost
12 of her balls to Usha. In round 2, Usha lost
12 of her total number of balls to Wendy. In round 3, Wendy lost
12 of her total number of balls to Tammy. In the end, Tammy, Usha and Wendy had 129, 93 and 61 balls respectively. How many balls did Usha have at first?
|
Tammy |
Usha |
Wendy |
Before 1 |
2 b |
118 |
|
Change 1 |
- 1 b |
+ 1 b |
|
After 1 |
1 b |
186 |
|
Before 2 |
68 |
2 u |
|
Change 2 |
|
- 1 u |
+1 |
After 2 |
|
1 u |
122 |
Before 3 |
|
|
2 p |
Change 3 |
+ 1 p |
|
- 1 p |
After 3 |
|
|
1 p |
Comparing Tammy, Usha and Wendy in the end |
129 |
93 |
61 |
Working backwards.
1 p = 61
At the start of Round 3:
Number of balls that Wendy had
= 2 p
= 2 x 61
= 122
At the start of Round 2:
Number of balls that Tammy had
= 129 - 1 p
= 129 - 61
= 68
At the end of Round 3:
Number of balls that Usha had = 93
1 u = 93
At the end of Round 1:
Number of balls that Usha had
= 2 u
= 2 x 93
= 186
1 b = 68
At the end of Round 1:
Number of balls that Tammy had = 68
At the start of Round 1:
Number of balls that Usha had
= 186 - 1 b
= 186 - 68
= 118
Answer(s): 118