The digit in the unit's place of the number (67)25 - 1 must be -
B. 6
C. 8
D. None of these
Answer: Option B
Solution (By Examveda Team)
Unit digit of (67)25 = Unit digit of 725Unit digit of 74 is 1 and so the unit digit of (74)6 is 1
∴ Unit digit of 725 = (1 × 7) = 7
Hence, the unit digit of (725 - 1) is (7 - 1) = 6
This Question Belongs to Arithmetic Ability >> Number System
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