Every telephone number consists of 7 digit How many telephone numbers are there Which do not include any other digit but 2,3,5 & 7?

How many 7- digit numbers are there?

How many 7-digit numbers are there?

How many numbers are there with: 7-digits

In a certain city, all telephone numbers have six digits How many telephone numbers are there with distinct digits?

In a certain city, all telephone numbers have six digits How many telephone numbers are there with all digits distinct and which start with 41 or 42 or 46 or 62 or 64

How many five-digit telephone numbers are there, the sum of whose digits is even ?

The number of five digit telephone numbers none of their digits being repeated is

In a certain city, all telephone numbers have six digits If repetition of digits is possible, how many telephone numbers are there in the city.