Question

The digit in the units place in the number $7^{289}$ is

• A. 9
• B. 7
• C. 1
• D. 3

Answer 1

Answer: (B)

7

Answer 2

Since, $7^{1}=7,7^{2}=49,7^{3}=343,7^{4}=2401$ Similarly, the next higher power of 7 comes out the same digits in the units place respectively. $\therefore$ digit at units place in $7^{289}=$ digit at units place in $\left(7^{4}\right)^{72} \cdot 7$ $=$ digit at units place in $1 \cdot 7$ The units place digit in $7^{289}$ is 7