Actually it is not correct.
I suspect the actual answer will surprise you:
That is repeated use of inclusion/exclusion rule.
We find the number of ways that at least one of is greater than or equal to six.
Then subtract that from the total.
Hey guys can you check to see if my answer is correct? Thanks!!
Use inclusion-exclusion to find the number of solutions in the non-negative integers to
.... with the conditions ,
Step 1: Find solutions with no conditions first.
Step 2: Get solutions for less than conditions
THEREFORE FINAL SOLUTION
Is this correct? thanks