COMEDK · Maths · 6. Mathematical Induction
The last digit in \(7^{300}\) is
- A \(7\)
- B \(9\)
- C \(1\)
- D \(3\)
Answer & Solution
Correct Answer
(C) \(1\)
Step-by-step Solution
Detailed explanation
We have, \[ \begin{aligned} &7^{1}=7 \\ &7^{2}=49 \\ &7^{3}=343 \\ &7^{4}=2401 \end{aligned} \] and so on. Thus, the last digit repeat itself in multiple of 4 . Since, 300 is divisible by 4 , the units digit of \(7^{300}\) would be 1 .
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