Question

When $2^{23}$ is divided by 10, the remainder will be

• A. 2
• B. 3
• C. 4
• D. 8

Answer 1

The correct option is D 8

Remainder by 10 in finding the unit's digit. The digit at unit's place in powers of 2 repeats itself after power 4.
On dividing 23 by 4, we get 3 as remainder.
Therefore, unit's digit will be the unit digit of $2^3=8$
Hence, remainder on division by 10 = 8