📊 GMAT Exam Prep

What is the units digit of 3^100?

A 1
B 3
C 7
D 9

✓ Correct Answer: Option A

The units digits of powers of 3 follow a cycle of 4: (3, 9, 7, 1). Since 100 is perfectly divisible by 4, the units digit will be the last in the cycle, which is 1.

💡 Why is A) the correct answer?

The correct answer to the question "What is the units digit of 3^100?" is Option A: 1.

The other options — B) 3, C) 7, D) 9 — are incorrect for this GMAT Exam Prep question. As explained above: The units digits of powers of 3 follow a cycle of 4: (3, 9, 7, 1). Since 100 is perfectly divisible by 4, the units digit will be the last in the cycle, which is 1.

📚 About This GMAT Exam Prep Practice Question

This 3-level GMAT 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 GMAT Exam Prep practice test or use flashcards for spaced repetition review.

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