If A : B = 2 : 3, B : C = 5 : 7 and C : D = 3 : 10,

If A : B = 2 : 3, B : C = 5 : 7 and C : D = 3 : 10, then what is A : D equal to ?

Here, A : B = 2 : 3, B : C = 5 : 7 and C : D = 3 : 10
∴ A/D = (A/B) x (B/C) x (C/D)
= (2/3) x (5/7) x (3/10)
= 1/7
∴ A : D = 1 : 7