A bag contains 7 tickets numbered 0,1,2,...6. Four tickets are drawn one by one with replacement. The probability that

the sum of the numbers on them is 8, is

 If in a frequency distribution the mean and median are 21 and 22 respectively, then its mode is approximately

Out of 13 group application for a job, there are 5 women and 8 men. It is desired to select to persons for the job. The

probability that at least one of the selected persons will be a women is

The marks of some students were listed out of 75. The SD of marks was found to be 9. Subsequently the marks were raised to a maximum of 100 and variance of new marks was calculated. The new variance is

A pair of dice thrown five times. The probability that doublets appear atleast 3 times is

One Indian and four American men and their wives are to be seated randomly around a circular table. Then the

conditional probability that the Indian man is seated adjacent to his wife given that each American man is seated

adjacent to his wife, is

Let A and B be two events such that

There are 5 balls numbered 1 to 5 and 5 boxes numbered 1 to 5. The balls are kept in the boxes one in each box. The

probability that exactly 2 balls are kept in the corresponding numbered boxes and the remaining 3 balls in the wrong

boxes, is

There are 2 teams with n persons in each; The probability of selecting 2 persons from one team  and 1 person from the other team is 6/7 then n is equal to

A and B are events such that