The area of the region bounded by the curve $y = x^3$ and the lines $y = 8$ and $x = 0$ is ... square units.

The differential equation of $3y = \sqrt[3]{x+c}$ is

The general solution of the differential equation $(x+y)\dfrac{dy}{dx} = 1$ is

A body cools according to Newton's law of cooling from $100^\circ$C to $60^\circ$C in $20$ minutes. The temperature of the surroundings being $20^\circ$C, then the total time required for the body to cool down to $30^\circ$C is