A person can do a job in 6 days. Another can do the same job in 4 days. If they work together, how long do they need to finish the job?

5 days

Step-by-step explanation:

This would have to do with average. So if one does it in 6 days and the other does it in 4 days, you would do the number between them. So 5 is between 4 and 6.

The more complicated way of thinking of it is like this...

add 6 and 4           6+4     that  would  =   10

Because we added two numbers, we have to divide by two.

10/2      which equals 5.

If it was numbers closer together like. 6 and 7 the middle numbeR would be 6.5 for example.

I hope this helped!!