The letters of the word LUCKNOW are arranged among themselves. The probability that the letters 'NOW' always appear together is:

If the letters of the word "TIRUPATI" are written down at random, then what is the probability that both Ts are always consecutive ?

The probability of getting the sum as a prime number, when two dice are thrown together, is :

Three different numbers are selected at random from the first 15 natural numbers. What is the probability that the product of two of the numbers is equal to third number?

Twelve Tickets are numbered from 1 to 12. If one ticket is selected at random, then the probability that the number on the ticket is a multiple of 2 or 3 is :

In a bag, there are 8 red, 7 yellow and 6 green balls. If one ball is picked up at random, what is the probability that it is neither red nor green?