If P ∶ Q = 9 ∶ 1, Q ∶ R = 1 ∶ 8 and R ∶ S = 1 ∶ 10, then what is the value of P ∶ R ∶ S respectively?
1
8 ∶ 9 ∶ 80
2
19 ∶ 18 ∶ 80
3
9 ∶ 8 ∶ 70
4
9 ∶ 8 ∶ 80
If P ∶ Q = 9 ∶ 1, Q ∶ R = 1 ∶ 8 and R ∶ S = 1 ∶ 10, then what is the value of P ∶ R ∶ S respectively?