GMAT Maths | GMAT Statistics Question Bank

This easy GMAT quant practice question is a problem solving question from Averages. Concept: Computing arithmetic mean or averages of a subset of a set of numbers. A GMAT 450 level statistics sample question.

Question 5: The average of 5 numbers is 6. The average of 3 of them is 8. What is the average of the remaining two numbers?

1. 4
2. 5
3. 3
4. 3.5
5. 0.5

---

---

Video Explanation

---

---

Explanatory Answer

The average of 5 quantities is 6.
Therefore, the sum of the 5 numbers is 5 × 6 = 30.

The average of three of these 5 numbers is 8.
Therefore, the sum of these three numbers = 3 × 8 = 24

The sum of the remaining two numbers = (Sum of all 5 - Sum of 3 numbers) = 30 - 24 = 6.

Average of these two remaining numbers = \\frac{6}{2}) = 3

Choice C is the correct answer.