Answer
$\approx40.17^{\circ}$
Work Step by Step
We know that:
$1"=\dfrac{1}{3600}^o$
$1'=\dfrac{1}{60}^o$.
Use a calculator and the conversion factors above to obtain:
$40^{\circ}10'25''\\
=40^o+\left(\frac{10}{60}\right)^o+\left(\frac{25}{3600}\right)^o\\
=40.1736^{\circ}\\
\approx40.17^{\circ}$
