Find A ∩ B if A = {4, 7, 10, 13, 17} and B = {3, 5, 7, 9}.

The answer is: A ∩ B = 7

Given: A = {4, 7, 10, 13, 17}

B = {3, 5, 7, 9}

By the symbol, ∩, we mean which terms/objects are common in the the sets given to us.

Since only, 7 is the only number which is present in both set A and set B.

Therefore, A ∩ B = 7