There are n letters and n addressed envelopes. Find the probability that all the letters are not kept in the right envelope.

There are 4 letters and 4 addressed envelopes. Find the probability that all the letters are not dispatched in right envelopes.

There are four letters and four directed envelopes. The number of ways in which all the letters can be put in the wrong envelope is a. 8 b. 9 c. 16 d. none of these

Three letters are dictated to three person and an envolopes at random so that each envelope contains exactly one letter. Find the probability that at least one letter is in its proper envelope.

If a coin be tossed n times, then find the probability that the head comes odd times.

A letter is chosen from English alphabet. Find the probability of the letters being a letter that comes after P

A letter is chosen from English alphabet. Find the probability of the letters being A vowel or a consonant

A letter is taken at random from the letters of the word GANGA" and another letter is taken at random from the letters of the word BANGA .The probability that the selected letters are the same is: