| Label one 20 litre drum A and the other drum
B, then do the following: |
Drum A |
Drum B |
Tin
(4) |
Bucket
(5) |
| Contents at the start: |
20 |
20 |
0 |
0 |
| Fill the 5 litre bucket
from drum A. |
15 |
20 |
0 |
5 |
| Fill the 4 litre tin
from the 5 litre bucket, leaving 1 litre in the bucket. |
15 |
20 |
4 |
1 |
| Empty the 4 litre tin
into drum A. |
19 |
20 |
0 |
1 |
| Pour the
litre from the bucket into the tin. |
19 |
20 |
1 |
0 |
| Again fill the 5 litre bucket
from drum A |
14 |
20 |
1 |
5 |
| Add water from the bucket to the 1 litre in the tin; that leaves
2 litres in the bucket. |
14 |
20 |
4 |
2 |
| Again empty the 4 litre tin into drum A. |
18 |
20 |
0 |
2 |
| Fill the 4 litre tin
from drum B. |
18 |
16 |
4 |
2 |
| Finally fill drum A from the 4
litre tin; leaving 2 litres in the tin. |
20 |
16 |
2 |
2 |
