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How many different telephone numbers of 7 digits can be formed if the first cannot be zero?
Wiki User
∙ 12y ago
There are a number of issues with this question. Phone numbers are limited to more than just the first number not being 0. What about 9-1-1? What about 4-1-1, or 5-1-1, or 3-1-1? What about 1-Area-Number? What about 1-0-Carrier-country-1-city-number? What about the fact that some exchanges do not permit a 0 or a 1 as the second digit of the number? What about the fact that the sum of the first and third digits are constrained to not be certain sums? (The last two rules are to prevent older rule-base auto-long-distance dialing detection logic from misdetecting an area code.) What about constraints on the last four digits.
With that said, and with only the constraints imposed by the question, i.e. ignoring these other known constraints, there are 9,000,000 different phone numbers in one exchange.
Wiki User
∙ 12y ago
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How many even four digit numbers can be made using 02356 where the first digit is cannot be 0 and no digits are repeated?
Assuming that 2356 is a different number to 2365, then: 1st digit can be one of four digits (2356) For each of these 4 first digits, there are 3 of those digits, plus the zero, meaning 4 possible digits for the 2nd digit For each of those first two digits, there is a choice of 3 digits for the 3rd digit For each of those first 3 digits, there is a choice of 2 digits for the 4tj digit. Thus there are 4 x 4 x 3 x 2 = 96 different possible 4 digit numbers that do not stat with 0 FM the digits 02356.
How many 5 numbers combinations can you make from 1 2 3 4 5?
If digits can be reused, then 5x5x5x5x5 = 3125. If digits cannot be reused, then 5x4x3x2x1 = 120.
Using four different digits what is the least sum you can get when you add two digit numbers?
2222
How many six digit numbers can be formed using the digits 0123456789 Example equals 123456 or 098765?
The number of six digit numbers that you can make from ten different digits ifrepetitions of same digit on the six digit number is allowed is 1 000 000 numbers(including number 000 000).If no repetitions of the the same digit are allowed then you have:10P6 = 10!/(10-6)! = 151 200 different six digit numbers(six digit permutations form 10 different digits).
How many five digits numbers can be formed using 01234 without repetition assuming that number cannot begin with 0?
There are 4*4*3*2*1 = 96 such numbers.
How many digits are there in Dubai telephone numbers?
7
How many 6-digits telephone numbers can have one or more repeated digits?
763920
Why were the first telephone numbers only a couple of digits?
because they didnt know the other digits.
How many digits are there in Turkish telephone numbers?
Telephone numbers in Turkey consist of the telephone country code +90, followed by a three-digit area code and a 7-digit subscriber number.
How many seven digit telephone numbers are possible if the first number is not allowed to be 0 or 1?
8,000,000 million telephone numbers are possible with these conditions, corresponding to the numbers 2,000,000 - 9,999,999. Many countries have forced dialing of the area code now, creating telephone numbers with a minimum of 10 digits. This means there are 8 million possible telephone numbers in each area code. (area code of 3 digits long).
What is the number of 5 digit telephone numbers having atleast one of their digits repeated?
5 digit telephone numbers having at least one of their digits repeated is = total possible 5 digit telephone numbers - 5 digit telephone numbers without any digit being repeated. =(10*10*10*10*10)-(10*9*8*7*6) =100000-30240 =69760
How many digits are there in a phone number in Russia?
Telephone numbers throughout Russia are uniformly 3 digits for the area code plus 7 digits for the local number.
Can you put this number in order -11.111 -111.11 1.11 11.1 -11.1 -1.11?
Answer: I cannot answer this question. I do not know where the numbers start and end. Answer: Put negative numbers before positive numbers. For the positive numbers, the one with the least digits is smaller. For the same number of digits, compare each digit until you find a different number of digits. For the negative numbers, it is the opposite as for positive numbers.
How many digits does Lesotho number have?
A telephone number in Lesotho are eight digits long with the first two numbers being its area code.
How many 3 digit numbers can be formed from the digits 12345 if the digits cannot be repeated?
1 set
The total number of five digit numbers that can be be formed digits 12345 is?
It is 120 if the digits cannot be repeated.
How many different numbers can you make using 5 different digits?
89,999 different numbers i guess
