Question

Let A = {1, 3, 5, 7, 9} & B = {2, 3, 5, 7, 11, 13}. Find A∩B?

Answer 1

Hint: For finding A∩B, we need to know what A∩B is. It is the number of elements common in both the sets A and B. In the above problem, look through set A and set B and segregate the number of elements common in both the sets and write these segregated elements under A∩B.

Complete step-by-step answer:
From the chapter of sets, we know that:

A∩B is the intersection of the two sets A and B.

In the above figure, 2 sets A and B are given and the shaded region is the area common in both the sets and it is also called as A∩B.

Number of elements given in the set A is as follows:

A = {1, 3, 5, 7, 9}

Number of elements given in the set B is as follows:

B = {2, 3, 5, 7, 11, 13}

As you can see from both the sets that 3, 5, 7 are the common elements among both the sets.

So, A∩B is equal to 3, 5 and 7.

Hence, A∩B = {3, 5, 7}.

Note: You might think that in the intersection of sets A and B, the set size of both the sets should be equal. It is not necessary that the size of the sets be similar. And don’t confuse with the symbols like “∪” stands for Union and “∩” stands for intersection. To eliminate confusion as “Union” starts with “U” so you can remember “U” for “Union” and the remaining will be intersection.