Ajit is too slow to win the race. ( Remove too)

In a horse -race, the probabilities to win the race for three horses A,B and C are 1/4,1/5 and 1/6 respectively. Find the probability to win the race of any one horse.

Photochemical fluorination is explosive while iodination si too slow to occur.The reason for this is:

* In a race,the probability of A to win the race is (1)/(7) and of B is (1)/(4). Find the probability that any one of them win the race