Thousand solid metallic spheres of diameter 6 cm are melted and recast into a new solid sphere. The diameter of the new sphere (in cm ) is
30
90
45
45
1980
1981
1983
1983
500 tonnes
1000 tonnes
5000 tonnes
5000 tonnes
15%
30%
50%
50%
D.
50%
Required percentage increase:
1980 and 1981
1982 and 1983
1984 and 1985
1984 and 1985