Find the whole quantity if, 40% of it is 500 km.

Let, the whole value be x

Given, 40% of x = 500 km

$\Rightarrow$$\frac{40}{100}$$\times$x = 500

$\Rightarrow$x = $\frac{500 \times 100}{40}$

$\Rightarrow$x = 1250 km

$\therefore$ the whole quantity is 1250 km.