Problem Solving

Q: A cask of 20 litres is filled with beer. A beer vendor has only two measuring vessels of 3 litres and 5 litres without any calibration. He has to measure four litres of beer for a customer without using any other vessel. Minimum how many operations are required for this work, where an operation is counted if the beer is transfered from one vessel to another vessel.

a) 5

b) 6

c) 8

d) 11

e) 14

Hi,
Is filling a vessel from Cask and transferring beer from vessel to Cask counted as operations?
If so, Let the 3 litre vessel be A and 5 litre vessel be B
Step-1: Fill B to the brim.
Step-2: Transfer beer from B to A(to the brim).
Step-3: Transfer beer from A to cask
Step-4: Transfer B to A...A now has 2 litres.
Step-5: Fill B to the brim
Step-6: Transfer beer from B to A(to the brim). So, B now has 5-1 = 4litres.
I am not very clear which of these transfers are considered operations.

1. Fill the 5 litres jug.
2. Fill the 3 litre jug using this 5 litre; the 5 litre now has 2 litres left. Give this to the customer.
3. Empty both jugs.
4. Fill 5 litre again.
5. Fill the 3 litre jug using this 5 litre; the 5 litre now has 2 litres left. Give this to the customer. This makes it 4 litres

So 5 steps .... A

Frankenstein wrote:Hi,
Is filling a vessel from Cask and transferring beer from vessel to Cask counted as operations?

Yes, filling a vessel from cask and vice versa each counts as operations. OA[spoiler]c) 8[/spoiler]

akhilsuhag wrote:1. Fill the 5 litres jug.
2. Fill the 3 litre jug using this 5 litre; the 5 litre now has 2 litres left. Give this to the customer.
3. Empty both jugs.
4. Fill 5 litre again.
5. Fill the 3 litre jug using this 5 litre; the 5 litre now has 2 litres left. Give this to the customer. This makes it 4 litres

So 5 steps .... A

First, we have to get a measure of 4 litres so giving in between to customer will not count as getting a measure of 4 litres.Therefore we cannot give in between. Next your step 3-- empty both jugs will count as two steps.

Aman verma wrote:

Frankenstein wrote:Hi,
Is filling a vessel from Cask and transferring beer from vessel to Cask counted as operations?

Yes, filling a vessel from cask and vice versa each counts as operations. OA[spoiler]c) 8[/spoiler]

Okay... But I am getting answer 6 and the OA is 8?

It is 6 I guess.Frank,I think you have covered all the available operations including the emptying tasks.

Please correct me If I am wrong.

It should be 6 only frank.