1.  If P : Q = 8 : 15, Q : R = 5 : 8 and R : S = 4 : 5, then P : S is equal to
A. 4 : 15
B. 2 : 15
C. 3 : 19
D. 7 : 15
E. None of the above

Answer: Option A

Explanation:

Given, P/Q = 8/15, Q/R = 5/8, R/S = 4/5
∴ P/S = (P/Q) x (Q/R) x (R/S)
⇒ P/S = (8/15) x (5/8) x (4/5) = 4/15
∴ P : S = 4 : 15