In a group of 500 people, 350 are engineers, 250 are MBA. Find how many people are both engineers and MBA?
I believe there is insufficient information given in the question.
My teacher gave $100$ as answer, based on $350 + 250 - 100$.
$(A \cup B)$ is not the same thing as total number of people, right?
But, what if there are people that are neither engineers or MBA?