If P ∶ Q = 9 ∶ 1, Q ∶ R = 1 ∶ 8 and R ∶ S = 1 ∶ 10, then what is the value of P ∶ R ∶ S respectively?
A8 ∶ 9 ∶ 80
B19 ∶ 18 ∶ 80
C9 ∶ 8 ∶ 70
D9 ∶ 8 ∶ 80
Answer:
D. 9 ∶ 8 ∶ 80
Read Explanation:
Calculation:
P : Q = 9 : 1,
Multiplied by 8 (to match with the 'Q : R' ratio)
⇒ P : Q = 72 : 8
⇒ Q : R = 1 : 8
Now, P : R = 72 : 64
R : S = 1 : 10,
Multiplied by 64 (to match with the 'P : R' ratio)
⇒ R : S = 64 : 640
⇒ P : R : S = 72 : 64 : 640
∴ The required ratio P: R : S is 9 : 8 : 80.