Question

In a group of 68 students, each student is registered for at least one of three classes – History, Math and English. Twenty-five students are registered for History, twenty-five students are registered for Math, and thirty-four students are registered for English. If only three students are registered for all three classes, how many students are registered for exactly two classes?A. 13B. 10C. 9D. 8E. 7

Answer 1

Answer:

c.10

Explanation:

We have 68 students, 3 of them are registered in three classes, so (68-3 =65), 65 students are registered in one or two classes.

Additionally, we know that:

• 25 students are registered for History.
• 25 students are registered for Math
• 34 students are registered for English

If we want to know only the registrations of students that are registered for one or two classes, we should substract 3 in every class (the three students that ar registered for the three classes)

So, now we have:

• 22 students registered for History.
• 22 students registered for Math
• 31 students  registered for English

Total registrations for stdents registered in one or two clases: 22+22+31= 75

75 registrations of 65 students

So 75-65=10 .. There are 10 students registered for 2 classes.