Question

How can you decide if finding common multiples or common factors is helpful in solving problems

Answer 1

it depends if you like working with big numbers or not. if you are working with large numbers and you want to bring them down you can use factors. multiples are easier to work with when multiplying to cancel out and make your sum easier

Answer 2

Suppose, John arranges stack of Gold and Silver coins in such a way that each stack either contains Gold or contains Silver coins only.

He also tries to arrange them in the least area.

Here, the number of coins in each stack is the common factor of number of Gold and Silver coins.

If we find the highest common factor, then the area occupied by the coins will be least.

Hence, in this situation, we have to find the common factor.

Suppose, George and David are walking along the circular pathway of a park with different speeds.

The problem is to find the time after which they will meet again at the starting point.

Clearly, here the required time is the common multiple of independent time taken by both.