Question

Of the students in Grayson's class, 7 have been to San Diego and 11 have been to Dallas. 5 students have been to both San Diego and Dallas. How many students have been to San Diego or Dallas or both?

A. 13

B. 15

C. 18

D. 23

Answer 1

To determine the number of students who have been to either San Diego, Dallas, or both, we apply the principle of inclusion-exclusion, which gives us a total of 13 students. Hence, the correct answer is A. 13.

Step-by-step explanation:

The question asks to find the number of students in Grayson's class who have been to San Diego or Dallas or both. To find this, we need to apply the principle of inclusion-exclusion. This principle states that if we want to find the total number of elements in the union of two sets, we should add the total number in each set and subtract the number that are in both sets (since they have been counted twice).

Using the principle:

• Number who have been to San Diego: 7
• Number who have been to Dallas: 11
• Number who have been to both San Diego and Dallas: 5

So, the total number of students who have been to either San Diego, Dallas, or both would be:

7 (San Diego) + 11 (Dallas) - 5 (Both) = 13 students.

Therefore, the correct answer is A. 13.