Seven chits are numbered 1 to 7. Four chits are drawn one by one with replacment. The probability that the least number appearing on any selected chit is 5 is :

Fifteen coupens are numbered 1,2,3,...15 respectively.Seven coupons are selected at random one at a time with replacement The Probability that the largest number appearing on a selected coupon is 9 is :

Fifteen coupons are numbered 1, 2, 3,…, 15 respectively. Seven coupons are selected random one at a time with replacement. The probability that the largest number appearing on the selected coupons is atmost 9, is :

A box contains tickets numbered 1 to 20.3 tickets are drawn from the box with replacement. The probability that the largest number on the tickets is 7, is

A bag contains 10 tickets numbered 1 to 10. Tickets are drawn one by one without replacement.Find the probability that the ticket number 7 is drawn at 4^(th) draw.

A box contains 10 tickets numbered from 1 to 10 . Two tickets are drawn one by one without replacement. The probability that the "difference between the first drawn ticket number and the second is not less than 4" is