Question

The number of odd positive integers, the logarithm of whose reciprocal to the base 3 have characterstic -5 , is

• A. 81
• B. 82
• C. 161
• D. 162

Answer 1

Answer: (A)

$-5<{\log }_3\frac{1}{N}<-4\Rightarrow 3^4<N\le 3^5\Rightarrow N=\{83,\dots \dots .,241,243\}$