In a race, the odds in favour of cars P, Q, R, S are 1 : 3, 1 : 4, 1 : 5 and 1 : 6 respectively. Find the probability that one of them wins the race.  Choose one:
A) 9/17
B) 114/121
C) 319/420
D) 27/111
E) 37/111
P(P) = 1/4, P(Q) = 1/5, P(R) = 1/6 and P(S) = 1/7.   All the events are mutually exclusive and hence,   the required probability:   = P(P) + P(Q) + P(R) + P(S)   = 1/4 + 1/5 + 1/6 + 1/7   = 319/420   ANSWER:319/420
<result>C</result>
In a race, the odds in favour of cars P, Q, R, S are 1 : 3, 1 : 4, 1 : 5 and 1 : 6 respectively. Find the probability that one of them wins the race.