Question

Find the rightmost non-zero integer of the expression ${1430}^{343}+{1470}^{367}$?

• A. 3
• B. 9
• C. 7
• D. 1

Answer 1

The correct option is C 7

It can be easily observed that ${1470}^{367}$ has more number of zeroes as compared to ${1430}^{343}$.

Hence, the rightmost non-zero integer will depend on the unit digit of only ${1430}^{343}$, which in turn will depend on the unit digit of $3^{343}$.

343 can be written as 4k+3. In the power cycle of 3 (3,9,7,1), the third digit is 7. Hence, the last non-zero integer in the expression is 7.