The rightmost non-zero digit of the number 302720 is
A. 1
B. 3
C. 7
D. 9
Answer: Option A
Solution (By Examveda Team)
(30)2720, we can write it as[(30)4]680Or,[(10 × 3)4]680
The right most non-zero digit depends on the unit digit of [(3)4]680
Unit digit of [(3)4]680,
Or, (81)680
The unit digit of 81 is 1 so any power of 81 will always give its unit digit as 1
Thus, required unit digit is 1
This Question Belongs to Arithmetic Ability >> Number System
Why we are not taking power less than 4 or greater than 4. How we should decide which pwer is give correct answer.