A. 2
B. 4
C. 8
D. 6
E. 0

Answer: C

Explanation:

Concept:
Every digit (0,1,2, 3,…..9) when raised to a power follows a pattern, i.e., there is a cyclicity in the values of units digits when raised to powers.

The pattern for 2:
2^1 - 2
2^2 - 4
2^3 - 8
2^4 - 16

So, if we look at it the unit’s digit pattern for 2 raised to a positive integer is 2, 4, 8 and 6 in that order.
So, to find the unit’s when 2 is raised to any positive integer power, take the power and divide it by 4,
If the
Rem 1 – it ends with 2
Rem 2 – it ends with 4
Rem 3 – it ends with 8
Rem 0(divisible by 4) – it ends with 6

Given,
Unit’s place of 2^99
Note that,
99 divided by 4 remainder is three. So, it ends with 8.

Hence the answer is C.

X

Talk to an expert?

Leave a Reply

Your email address will not be published.