A shopkeeper has one laddoo of radius 5 cm.

Volume of laddoo having radius = 5 cm

i.e Volume $\left(V_{1}\right)=4 / 3 \pi r^{3}$

$\left(V_{1}\right)=4 / 3 \times 22 / 7 \times(5)^{3}$

$\left(\mathrm{V}_{1}\right)=11000 / 21 \mathrm{~cm}^{3}$

Also Volume of laddoo having radius 2.5 cm

i.e Volume $\left(V_{2}\right)=4 / 3 \pi r^{3}$

$\left(V_{2}\right)=4 / 3 \times 22 / 7 \times(2.5)^{3}$

$\left(\mathrm{V}_{2}\right)=1375 / 21 \mathrm{~cm}^{3}$

Therefore number of laddoos = V1/V2 = 11000/1375 = 8