The number of 3- digit numbers containing the digit 7 exactly once :

The number of five digit numbers that contains 7 exactly once is equal to

The number of 5 digited numbers that contain 7 exactly once is

The number of five-digit numbers that contain 7 exactly once is a. (41)(9^3) b. (37)(9^3) c. (7)(9^4) d. (41)(9^4)

The number of five-digit numbers that contain 7 exactly once is a.(41)(9^(3)) b.(37)(9^(3)) c. (7) (9^(4)) d.(41)(9^(4))

The number of five-digit numbers that contain 7 exactly once is a. (41)(9^3) b. (37)(9^3) c. (7)(9^4) d. (41)(9^4)

The number of 5 digits numbers that contain 7 exactly once is

The number of 6 digit numbers that contains 6 exactly once is _________ .

The number of 6 digit numbers that contains 6 exactly once is _________ .

The number of n-digit numbers which contain the digits 2 and 7, but not the digits 0,1,8,9, is