A cylindrical tank of radius $10$ m is filled with wheat at $314$ m$^3$/h. The depth of the wheat is increasing at the rate of (take $\pi=3.14$)

1. Volume $V=\pi r^2 h=\pi(100)h=100\pi h$. 2. $\dfrac{dV}{dt}=100\pi\dfrac{dh}{dt}$. 3. Set $=314$: $314=100\pi\dfrac{dh}{dt}=314\dfrac{dh}{dt}$. 4. $\dfrac{dh}{dt}=\dfrac{314}{314}=1$ m/h. 5. Trap $0.1$ misplaces a power of ten. _Source: NCERT Class 12 Mathematics Ch 6 "Application of Derivatives", p.38_