### Mymensingh higher secondary 2019#1

Posted:

**Sat Feb 23, 2019 1:20 pm**How many digits in the following number?

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

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

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Posted: **Sat Feb 23, 2019 1:20 pm**

How many digits in the following number?

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

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

Posted: **Sun Mar 10, 2019 4:06 pm**

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$=2017+4=\fbox {2021}$

Posted: **Sun Mar 10, 2019 4:20 pm**

Shouldn't it be $5^{2018}$ instead of $5^{2017}$?

Posted: **Sun Mar 10, 2019 4:25 pm**