The ratio of the radii of two spheres is 3 : 2. Find the ratio of their volumes.

25 : 4 5 : 16 9 : 14 27 : 8

27 : 8

$R_1:R_2=3:2$ $V_1:V_2=\frac{4}{3}πR_1^3:\frac{4}{3}πR_2^3$ $=R_1^3:R_2^3=27:8$