Quantitative Aptitude • Number System & SimplificationMedium
What is the unit digit of 3^87?
A. 3
B. 1
C. 9
D. 7✓ Correct Answer
💡 Solution & Explanation
The unit digits of powers of 3 repeat in a cycle of 4: 3, 9, 7, 1. Divide the power by 4: 87 ÷ 4 leaves a remainder of 3, which means position 3 in the cycle. So the unit digit of 3^87 is 7. Only the last digit of the base matters for this pattern.
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