\(\Delta x.\,\Delta v = \frac{h}{{4\pi m}}\)

                   [Heisenberg' uncertainty principle]

or \(\Delta x = \frac{h}{{4\pi m.\Delta v}}\)

Thus, \(\Delta {x_A} = \frac{h}{{4\pi  \times 0.05 \times m}}....(i)\)

          \(\Delta {x_B} = \frac{h}{{4\pi  \times 0.02 \times 5m}}....(ii)\)

Dividing \((i)\) by \((ii)\), we get 

\(\frac{{\Delta {x_A}}}{{\Delta {x_B}}} = \frac{{0.02 \times 5}}{{0.05}} = \frac{{10}}{5}\,or\,2\)