Thread: discrete mate

4. Let

A, B be finite sets. Recall that |A  B| = |A| + |B| - |A  B|. Find a similar formula
for |A  B  C| using formal proof.


thank q for who helping.......

Originally Posted by cclia

4. Let

A, B be finite sets. Recall that |A  B| = |A| + |B| - |A  B|. Find a similar formula
for |A  B  C| using formal proof.


thank q for who helping.......

Hello,



So consider

Now use the formula you're given :



This gives