Question

Find the remainder when ${123}^{33}$ is divided by 10.

• A. 3
• B. 9
• C. 7
• D. 1

Answer 1

The correct option is A

3

For remainder when a number is divided by 10, we need to check only the last digit.

We can write 33=4k+1. The first digit in the cycle of 3 = 3 (the cycle of 3 is 3,9,7,1)

${123}^{33}={123}^{4k+1}=...3$. Thus, the last digit of this number will be 3.