Online Course Discussion Forum
MC-II A Problems
Hi Eddy! This is Derek :D
So for 4.25, it is similar to problem 4.10 (if y'all got the time to do it in class) If not, you can refer to the textbook (if you have it); it has explanations on the back for problem 4.10.
Anyway, I think the best approach to this one is complementary counting and some PIE.
Hope this helps!