If ${\log }_{10}87.5=1.9421$, then the number of digits in ${\left(875\right)}^{10}$ is

Given ${\log }_{10}87.5=1.9421$

Take $x={\left(875\right)}^{10}.$

Now ${\log }_{10}x={\log }_{10}{\left(875\right)}^{10}$

$=10{\log }_{10}875$

$=10\left(2.9421\right)$

$=29.421$

Number of digits in ${\left(875\right)}^{10}=30$