A metallic sphere of diameter 40 cm is melted into smaller spheres of radius 0.5 cm. How many such small balls can be made?

32,000 3,200 64,000 6,400

64,000

We have a direct concept = Number of smaller sphere = (\(\frac{ radius \; of \; bigger \; sphere }{ radius \;  of \; smaller \; sphere }\))3  = (\(\frac{20}{0.5}\))3 = 403 = 64,000