What is the digit in the unit’s place of 2^51

What is the digit in the unit’s place of 251?

  1. 1
  2. 2
  3. 4
  4. 8

Answer

Last digit of any number shows a definite pattern.

21 (24n+1) = 2

22 (24n+2) = 4

23 (24n+3) = 8

24 (24n+4) = 6

25 (24n+1) = 32

Cyclicity of 2 is 4 → 2, 4, 8, 6

251 = 24n+3 

So, the digit in unit's place is 8.

The correct option is D.