A Container Explodes and Breaks into Three Fragments That Fly

A container explodes and breaks into three fragments that fly off 120° apart from each other,with mass ratios 1: 4: 2.If the first piece flies off with a speed of 6.0 m/s,what is the speed of the other two fragments? (All fragments are in the plane. )

A) 1.5 and 3.0 m/s
B) 0.9 and 3.0 m/s
C) 1.5 and 0.9 m/s
D) 1.0 and 3.0 m/s