64 solid iron spheres of radius r are melted to form a sphere of radius R. Find R : r.
Answer & explanation
Correct answer: option 4
64 solid iron spheres of radius r are melted to form a sphere of radius R.
Volume of 64 solid iron spheres of radius r = 64* 4Πr3/3
Volume of solid sphere R = 4ΠR3/3
Also, 4ΠR3/3 = 64* 4Πr3/3
R3 = 16* 4r3
R3 = (4r)3
The correct answer is Option (4) → 4 : 1