Q1 DIGIT PROPERTIES
What is the digit in unit’s place of 2^51?
a.2
b.8
c.1
d.4
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
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