A fair coin is tossed 6 times. What is the probability of getting a result in the 6^th toss which is different from those obtained in the first five tosses ?

If H is the Harmonic Mean of three numbers 10C4, 10C5, and 10C6, then what is the value of $\frac{270}{H}$ ?

In a class, there are n students including the students P and Q. What is the probability that P and Q sit together if seats are assigned randomly?

In a Binomial distribution B(n, p), n = 6 and 9P(X = 4) = P(X = 2). What is p equal to ?