Rachel, Tina and Kylie each had some marbles and decided to play a game with their marbles. In round 1, Rachel lost
12 of her marbles to Tina. In round 2, Tina lost
12 of her total number of marbles to Kylie. In round 3, Kylie lost
12 of her total number of marbles to Rachel. In the end, Rachel, Tina and Kylie had 118, 94 and 58 marbles respectively. How many marbles did Tina have at first?
|
Rachel |
Tina |
Kylie |
Before 1 |
2 b |
128 |
|
Change 1 |
- 1 b |
+ 1 b |
|
After 1 |
1 b |
188 |
|
Before 2 |
60 |
2 u |
|
Change 2 |
|
- 1 u |
+1 |
After 2 |
|
1 u |
116 |
Before 3 |
|
|
2 p |
Change 3 |
+ 1 p |
|
- 1 p |
After 3 |
|
|
1 p |
Comparing Rachel, Tina and Kylie in the end |
118 |
94 |
58 |
Working backwards.
1 p = 58
At the start of Round 3:
Number of marbles that Kylie had
= 2 p
= 2 x 58
= 116
At the start of Round 2:
Number of marbles that Rachel had
= 118 - 1 p
= 118 - 58
= 60
At the end of Round 3:
Number of marbles that Tina had = 94
1 u = 94
At the end of Round 1:
Number of marbles that Tina had
= 2 u
= 2 x 94
= 188
1 b = 60
At the end of Round 1:
Number of marbles that Rachel had = 60
At the start of Round 1:
Number of marbles that Tina had
= 188 - 1 b
= 188 - 60
= 128
Answer(s): 128