What will be the unit digit in the 7105 ?
A. 5
B. 7
C. 9
D. 1
Answer: Option B
Solution(By Examveda Team)
$$\eqalign{ & {{\text{7}}^{105}} \Rightarrow \cr & {{\text{7}}^1} \to 7 \to 7 \cr & {{\text{7}}^2} \to 49 \to 9 \cr & {{\text{7}}^3} \to 343 \to 3 \cr & {{\text{7}}^4} \to 2401 \to 1 \cr & {\text{Divided power of 7 by 4}} \cr & \frac{{105}}{4} \to {\text{ remainder = 1}} \cr & \Rightarrow {{\text{7}}^1}\,{\text{is left unit digit = 1}} \times 7 = 7 \cr} $$Related Questions on Number System
Three numbers are in ratio 1 : 2 : 3 and HCF is 12. The numbers are:
A. 12, 24, 36
B. 11, 22, 33
C. 12, 24, 32
D. 5, 10, 15
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