How many students passed only math?

How many students passed only math?

• A. 7
• B. 18
• C. 11
• D. 5

Answer: (C)

The key idea is to isolate the math-only group by removing anyone who also passed the other subject. You start with everyone who passed math, then subtract those who passed both math and the other subject. In this data, 18 students passed math in total, and 7 of them passed both subjects. So the number who passed only math is 18 − 7 = 11. That’s why 11 is the correct count. If you see other numbers, they would correspond to other parts of the distribution (such as those who passed both, or the total who passed math, etc.), but they don’t represent the math-only group given these totals.

The key idea is to isolate the math-only group by removing anyone who also passed the other subject. You start with everyone who passed math, then subtract those who passed both math and the other subject. In this data, 18 students passed math in total, and 7 of them passed both subjects. So the number who passed only math is 18 − 7 = 11. That’s why 11 is the correct count. If you see other numbers, they would correspond to other parts of the distribution (such as those who passed both, or the total who passed math, etc.), but they don’t represent the math-only group given these totals.