Answer
$=\dfrac {2}{5}=0.4$
Work Step by Step
$\lim _{t\rightarrow 25}\dfrac {3\sqrt {t}-\dfrac {1}{5}t}{\left( t-20\right) ^{2}}=\dfrac {3\times \sqrt {25}-\dfrac {25}{5}}{\left( 25-20\right) ^{2}}=\dfrac {15-5}{52}=\dfrac {10}{25}=\dfrac {2}{5}=0.4$
