a : b = 4 : 7 এবং b : c = 5 : 6 হলে a : b : c = কত?

A 4 : 7 : 6

B 20:35:24

C 20:35:42

D 24:35:30

Correct Answer: Option C

a:b = 4:7 = 4 × 5 : 7 × 5 = 20:35

b:c = 5:6 = 5 × 7 : 6 × 7 = 35:42

a:b:c = 20:35:42