The average (arithmetic mean) of 5 numbers is 18. If a new number is added to the set, the new average of the 6 numbers becomes 20. What is the value of the new number?

A 25

B 28

C 30

D 32

✓ Correct Answer: Option C

The sum of the initial 5 numbers is 5 * 18 = 90. After adding a new number, the sum of 6 numbers is 6 * 20 = 120. The value of the new number is the difference: 120 - 90 = 30.

💡 Why is C) the correct answer?

The correct answer to the question "The average (arithmetic mean) of 5 numbers is 18. If a new number is added to the set, the new average of the 6 numbers becomes 20. What is the value of the new number?" is Option C: 30.

The other options — A) 25, B) 28, D) 32 — are incorrect for this GRE Exam Prep question. As explained above: The sum of the initial 5 numbers is 5 * 18 = 90. After adding a new number, the sum of 6 numbers is 6 * 20 = 120. The value of the new number is the difference: 120 - 90 = 30.

📚 About This GRE Exam Prep Practice Question

This 2-level GRE Exam Prep question from the Quantitative Reasoning topic is part of BrainForge Quiz's free exam preparation library. Each question includes the correct answer and a detailed explanation to help you understand the underlying concept, not just memorize the answer.

How to use this page: Read the question above, consider all four options (A through D), then check the highlighted correct answer and explanation. For active timed practice, start a free GRE Exam Prep practice test or use flashcards for spaced repetition review.

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The average (arithmetic mean) of 5 numbers is 18. If a new number is added to the set, the new average of the 6 numbers becomes 20. What is the value of the new number?

✓ Correct Answer: Option C

📚 About This GRE Exam Prep Practice Question

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