From a box containing 20 tickets marked with numbers 1 to 20, four tickets are drawn one by one. After each draw, the ticket is replaced. The probability that the largest value of tickets drawn is 15 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 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 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 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 box contains tickets numbered 1 to N. n tickets are drawn from the box with replacement. The probability that the largest number on the tickets is k, is

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

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

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

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