Discussion

Explanation:

The required answer is nothing but the last digit of 9^13890000.

We know that the cyclicity of 9 is of 2 terms i.e.,

Last digit of 9^{odd number} = 9, and

Last digit of 9^{even number} = 1.

Here 13890000 is an even number, hence, last digit of 9^13890000 will be 1.

Hence, 1.

» Your doubt will be displayed only after approval.