What is the last digit of the decimal expansion of 1210Solu

__________ What is the last digit of the decimal expansion of 1/2^10?

Solution

Now, this is same as writing :

(1/2)(1/2)(1/2).... 10 times

(0.5)(0.5)(0.5) .... 10 times

Now, whenever we multiply 5 and 5, we get 25, which also has last digit
of 5

So, the final digit of the decimal expansion is :

5