posted by me .
A bucket contains 8m^3 of water. Using two smaller buckets of 3m^3 and 5m^3 respectively. How will you manipulate accurately so that only 4m^3 is left in d biggest bucket?
Remove 5 m^3 from the large bucket and pour 2 m^3 of that into the smallest bucket, filling it. Your buckets now contain: 3 m^3 (large), 3 m^3 (middle) and 2 m^3 (smallest).
Pour 3 m^3 from the middle bucket back to the largest bucket, leaving 6 m^3 there.
Throw away the 2 m^3 in the smallest bucket (or add it to the middle bucket)and refill it with 2 m^3 of water from the largest bucket. That will leave 4 m^3 there