If he has to work exactly 6 out of 10 and 3 out of the first 4, then he must work exactly 3 out of the last 6. Hence, the answer to this question is to be found in the sum of the number of ways to select 3 things from 4 things plus the number of ways to select 3 things from 6 things:
You can do your own arithmetic.
Hope this helps and please give me Brainliest!
