If A : B= 3 : 5 and B : C = 7 : 9, then A : B : C is:  Pick one:
A) 2:4:8
B) 21:35:45
C) 5:10:15
D) 12:24:36
E) 36:42:8
A:21:35:45=3:5, 21:35:45:C=7:9, A:21:35:45:C=3Ã—7:7Ã—5:5Ã—9   â‡’ 21:35:45   Answer: 21:35:45.
<result>B</result>
If A : B= 3 : 5 and B : C = 7 : 9, then A : B : C is: