Fanny, Victoria and Sarah each had some marbles and decided to play a game with their marbles. In round 1, Fanny lost
15 of her marbles to Victoria. In round 2, Victoria lost
15 of her total number of marbles to Sarah. In round 3, Sarah lost
15 of her total number of marbles to Fanny. In the end, Fanny, Victoria and Sarah had 126, 96 and 72 marbles respectively. How many marbles did Victoria have at first?
|
Fanny |
Victoria |
Sarah |
|
|
93 |
|
Before 1 |
5 b |
|
|
Change 1 |
- 1 b |
+ 1 b |
|
After 1 |
4 b |
120 |
|
Before 2 |
108 |
5 u |
|
Change 2 |
|
- 1 u |
+ 1 u |
After 2 |
|
4 u |
90 |
Before 3 |
|
|
5 p |
Change 3 |
+ 1 p |
|
- 1 p |
After 3 |
|
|
4 p |
Comparing Fanny, Victoria and Sarah in the end |
126 |
96 |
72 |
Working backwards.
4 p = 72
1 p = 72 ÷ 4 = 18
At the start of Round 3:
Number of marbles that Sarah had
= 5 p
= 5 x 18
= 90
4 u = 96
1 u = 96 ÷ 4 = 24
At the start of Round 2:
Number of marbles that Victoria had
= 5 u
= 5 x 24
= 120
At the start of Round 2:
Number of marbles that Fanny had
= 126 - 18
= 108
4 b = 108
1 b = 108 ÷ 4 = 27
At the start of Round 1:
Number of marbles that Victoria had
= 120 - 1 b
= 120 - 27
= 93
Answer(s): 93