CSAT: Unit Digit of 3⁵⁷ Quiz

Question

What is the unit digit of 3⁵⁷

Accepted Answer

To find the unit digit of 3⁵⁷, first observe the pattern of unit digits in powers of 3. 3¹ = 3 → unit digit 3 3² = 9 → unit digit 9 3³ = 27 → unit digit 7 3⁴ = 81 → unit digit 1 Now notice the pattern of unit digits: 3, 9, 7, 1 This pattern repeats every 4 powers. Next, divide the exponent 57 by 4 (since the cycle length is 4). 57 ÷ 4 gives a remainder of 1. This means we look at the 1st position in the repeating cycle. The 1st number in the pattern (3, 9, 7, 1) is 3. So, the unit digit of 3⁵⁷ is 3. Final Answer: 3 (Option B)

Answer

1

Answer

3

Answer

7

Answer

9

Options

Explanation

Solution

Step 1: Observe unit digit pattern of powers of 3

Step 2: Divide exponent by cycle length

Step 3: Final Answer

✅ Answer

Question