If $\log _{10}(3)=0.4771$ then the number of digits in $3^{40}$ is

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Professor PC Thomas Classes · Answer

Let $y=3^{40}$ $$ \log _{10}(y)=40 \log _{10}(3)=40 	imes 0.4771=4 	imes 4.771=19.084 $$ Here cha $=19 \Rightarrow$ number of digits $=20$