A body travels uniformly a distance of $\left(40.0\pm 0.1\right)m$ in time $\left(2.0\pm 0.04\right)s.$ The velocity of the body is

$V=\frac{S}{t}=\frac{40}{2}=20$ 

 $\frac{\Delta V}{v}=\frac{\Delta S}{s}+\frac{\Delta t}{t}\Rightarrow \Delta V=V\left[\frac{\Delta S}{s}+\frac{\Delta t}{t}\right]$

$$\begin{gathered} =20[\frac{0.1}{40}+\frac{0.04}{2}] \\ =0.45 \end{gathered}$$

$\Rightarrow V\pm \Delta V=20\pm 0.45$