Description : Twenty-seven solid iron spheres, -Maths 9th
Last Answer : (i) Volume of 27 solid sphere, each of radius, r = 27 x 4/3 πr3 = 36 πr3 According to statement, Volume of sphere of radius r' = Volume of 27 solid spheres ⇒ 4/3 π(r'3 ) = 36 πr3 ⇒ (r')3 = 27r3 = (3r)3 ⇒ r' = 3r ( ... πr'2 = 4 π(3r)2 = 36 πr2 ∴ S/S' = 4 πr2 /36 πr2 = 1/9 ⇒ S : S' = 1 : 9