If $y = e^{-mx}$ is a solution of the differential equation $\dfrac{d^2y}{dx^2} + 4\dfrac{dy}{dx} + 3y = 0$, then the values of $m$ are

For the differential equation $(x^2 + y^2)\,dy = xy\,dx$, it is given that $y(1) = 1$ and $y(x_0) = e$, then the value of $x_0$ is _____

For the differential equation $\dfrac{d^3y}{dx^3} + \cos\left(\dfrac{d^2y}{dx^2}\right) = 0$, which of the following is true ?

If water at $100^\circ\text{C}$ cools in 10 minutes to $80^\circ\text{C}$ and to $65^\circ\text{C}$ in the next 10 minutes, then the room temperature will be ...