Question

The hair company offers two brands of shampoo: brand Hand brand S.

100 people were surveyed and their brand preferences are. 70 liked brand
Hand 60 liked brand S. How many people liked both brand Hand S?*

Answer 1

In the photo

Explanation:

If A and B are two different events then, P(A U B) = P(A) + P(B) - P(A ∩ B)

Explanation of the formula:

If you look at the Venn Diagram, if you add 2 areas : P(A) and P(B), P(A ∩ B) is overlapping. This is why you should remove P(A ∩ B).

However, in this case, we should find P(A ∩ B) and all the other values are given in the question. Hence, we implement them and find P(A ∩ B).