Given 3A = 4B
MEANS 3/4 = B/A or 3:4 = B :A ------------------1
NOW 4B = 6C
means 4/6 = C/B OR 4 : 6 = C : B - OR 2 : 3 is C : B-------------------------- ----2
AND 3A = 6C
MEANS 3/6 = C/A or 3:6 = C : A
hence A ;B : C = 4 : 3 : 2 <---- is the answer!