Box 1 contains six block lettered A,B,C,D,E and F. Box 2 contains four blocks lettered W,X,Y and Z. How many five letters codewords can be formed by using three blocks from box 1 and two blocks from box2?

How many three letter words can be formed using a , b , c , d , e if Repetition is not allowed ii. repetition is allowed?

How many 4-letter words can be formed using a,b,c,d and e (i) without repetiton. (ii) with repetition.

Seven cards each bearing a letter , can be arranged to spell the word 'DOUBLES' .How many three - letter code- words can be formed from these cards ? How many of these words consist of a vowels between two consonants?

Box I contains two white and three black balls. Box II contains four white and one black balls and box III contains three white and four black balls. A dice having three red, two yellow and one green face, is thrown to select the box. If red face turns up, we pick up box I, if a yellow face turns up we pick up box II, otherwise, we pick up box III. Then, we draw a ball from the selected box. If the ball drawn is white, what is the probability that the dice had turned up with a red face?

Box A contains 2 black and 3 red balls, while box B contains 3 black and 4 red balls. Out of these two boxes one is selected at random, and the probability of choosing box A is double that of the probability of choosing box B. If a red ball is drawn from the selected box then find the probability that it has come from box B.

How many five letter words containing 3 vowels and 2 consonants can be formed using the letters of the word EQUATION so that the two consonants occur together?

Four letters E, K, S an V, one in each, were purchased from a plastic warehouse. How many ordered pairs of letters, to be sued as initials, can be formed from them?

A box contains a certain number of balls. On each of 60% balls, letter A is marked. On each of 30% balls, letter B is marked and on each of remaining balls, letter C is marked. A ball is drawn from the box at random. Find the probability that the ball drawn is : (iii) neither B nor C.

A box contains a certain number of balls. On each of 60% balls, letter A is marked. On each of 30% balls, letter B is marked and on each of remaining balls, letter C is marked. A ball is drawn from the box at random. Find the probability that the ball drawn is : (i) marked C

A box contains a certain number of balls. On each of 60% balls, letter A is marked. On each of 30% balls, letter B is marked and on each of remaining balls, letter C is marked. A ball is drawn from the box at random. Find the probability that the ball drawn is : (ii) A or B