How many digits in the following number?
$2^{2017}\times 7^3\times 5^{2018}$
Mymensingh higher secondary 2019#1
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Please don't post problems (by starting a topic) in the "X: Solved" forums. Those forums are only for showcasing the problems for the convenience of the users. You can always post the problems in the main Divisional Math Olympiad forum. Later we shall move that topic with proper formatting, and post in the resource section.
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Re: Mymensingh higher secondary 2019#1
Answer
$\fbox {2021}$
$Sol^n$
\[2^{2017}\times 5^{2018}\times7^3\]
\[=10^{2017}\times 5\times 343\]
\[=10^{2017}\times 1715\]
\[=1715\underbrace{000\cdots 0}_{2017}\]
So total digit$=2017+4=\fbox {2021}$
$\fbox {2021}$
$Sol^n$
\[2^{2017}\times 5^{2018}\times7^3\]
\[=10^{2017}\times 5\times 343\]
\[=10^{2017}\times 1715\]
\[=1715\underbrace{000\cdots 0}_{2017}\]
So total digit$=2017+4=\fbox {2021}$
Last edited by samiul_samin on Sun Mar 10, 2019 4:24 pm, edited 1 time in total.
Re: Mymensingh higher secondary 2019#1
Shouldn't it be $5^{2018}$ instead of $5^{2017}$?
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