How many digits in the following number?

$2^{2017}\times 7^3\times 5^{2018}$

## Mymensingh higher secondary 2019#1

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- samiul_samin
**Posts:**999**Joined:**Sat Dec 09, 2017 1:32 pm

### 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 $5^{2017}$?

- samiul_samin
**Posts:**999**Joined:**Sat Dec 09, 2017 1:32 pm