How many seven-digit numbers are there when 0 and 8 cannot be the leading number? There are 7 그 such seven-digit numbers.

Question

How many seven-digit numbers are there when 0 and 8 cannot be the leading number?
There are
7 그 such seven-digit numbers.

in progress 0
Diễm Thu 4 years 2021-08-10T02:28:15+00:00 1 Answers 23 views 0

Answers ( )

  1. Sigrid
    0
    2021-08-10T02:29:27+00:00
    Reply

    It is given that leading number cannot be 0 and 8 . So, choices are :

    [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 9 ] i.e 8 choices.

    Now, choices of other six digits are [ 0, 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8, 9 ] i.e 10 choices.

    So, number of seven digits with given constraint is :

    N = 8×10×10×10×10×10×10

    N = 8000000

    Therefore, seven-digit numbers with given constrain are 8000000.

    Hence, this is the required solution.

Leave an answer

Browse

Giải phương trình 1 ẩn: x + 2 - 2(x + 1) = -x . Hỏi x = ? ( )