Given log<sub>10</sub>2 = 0.30103, find the number of digits in 2<sup>64</sup>.
Aptitude
Logarithm
Difficulty: Medium
Choose an option
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A19
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B20
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C21
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D22
Answer
Correct Answer: 20
Explanation
Concept / Approach
- The number of digits of a positive integer N in base 10 is ⌊log10N⌋ + 1.
Step-by-step calculationlog10(264) = 64 × log102 = 64 × 0.30103 = 19.26592Digits = ⌊19.26592⌋ + 1 = 19 + 1 = 20
Common pitfalls
- Rounding 19.26592 before taking the floor. Always floor first, then add 1.
Final Answer20