List of top Mathematics Questions on Significant figures

The minimum value of the function $f(x)=\int\limits_0^2 e^{|x-t|} d t$ is :

The minimum value of the function $f(x)=\int\limits_0^2 e^{|x-t|} d t$ is :

If $Log_{10}7=0.8451$ then the position of the first significant figure of $7^{-20}$ is