Contextual Applications of Differentiation · Challenge problem

A quantity of gas obeys $PV=5T$ (with $P$ in kPa, $V$ in liters, $T$ in kelvin) while the amount of gas stays fixed. At an instant when $V=10$ L is increasing at $0.5$ L/s and $P=20$ kPa is decreasing at $0.4$ kPa/s, find the rate of change of $T$.