There sre three letters asnd three envelopes. Find the total number of wys in which letters can be put into the envelopes so that each envelope has only one letter.

There are 5 letters and 5 directed envelopes. The number of ways in which all the letters can be put in wrong engvelope, is

There are 3 letters and 3 directed envelopes. Write the number of ways in which no letter is put in the correct envelope.

Ravish writes letters to his five friends and addresses the correspondig envelopes. The total number of ways in which letters can be placed in the envelopes so that at least two of them are in the wrong envelopes, is

If the number of ways in which 7 letters can be put in 7 envelopes such that exactly four letters are in wrong envelopes is N, then

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

The number of ways in which four different letters can be put in their four addressed envelopes that

There are seven even greeting cards each of a different colour and seven envelopes of the same seven colours. Find the number of ways in which the cards can be put in the envelopes so that exactly four of the cards go into the envelopes of the right colour.

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

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

There are 6 letters and 6 addressed envelopes. Find the probability that at least one letter goes into the wrong envelope.