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How many 7 digit phone numbers are available if a digit can only be used once and the first number can not be 0 or 1?
Wiki User
∙ 16y ago
560135
Micron: wished you had posted the logic. As I see it, the first can be one of 8 digits. The second number can be 0 or 1 but not the same as the first (9 to choose from). The third cannot be the same as either of the first two (8 to choose from), etc. Thus it would be 8*9*8*7*6*5*4=483,840
Wiki User
∙ 16y ago
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How do 3 digit numbers compare to 4 digit numbers?
3 digit numbers are lessthan 4 digit numbers
Name a 10 digit Number such that the first digit on the left tells how many 0 are in the numbers?
1234567890
How many different 7-digit telephone members are possible if the first digit can not be zero and no digit repeat?
There are 10 possible numbers that can be chosen. Since the first digit can't be 0, there are 9 selections for the first digit. The second number can include a 0, but can't include the first number chosen, so there are 9 selections for the second digit. Then there are 8 digits for the next number, 7 digits for the next number, and so on. Total telephone numbers are: 9*9*8*7*6*5*4 = 544320 phone numbers.
How many 3 digit number are such that their first digit equals the sum of the last two digit?
There are 54 such numbers.There are 54 such numbers.There are 54 such numbers.There are 54 such numbers.
What is the smallest three digit number divisible by the first three prime number and the first number three composite numbers?
120
How do 3 digit numbers compare to 4 digit numbers?
3 digit numbers are lessthan 4 digit numbers
How many 8 digit number are there in total?
The first 8 digit number is 10,000,000, the last is 99,999,999 which means there are 90,000,000 8 digit numbers
How many four digits numbers can be formed using 0123456789?
Assuming that the first digit of the 4 digit number cannot be 0, then there are 9 possible digits for the first of the four. Also assuming that each digit does not need to be unique, then the next three digits of the four can have 10 possible for each. That results in 9x10x10x10 = 9000 possible 4 digit numbers. If, however, you can not use the same number twice in completing the 4 digit number, and the first digit cannot be 0, then the result is 9x9x8x7 = 4536 possible 4 digit numbers. If the 4 digit number can start with 0, then there are 10,000 possible 4 digit numbers. If the 4 digit number can start with 0, and you cannot use any number twice, then the result is 10x9x8x7 = 5040 possilbe 4 digit numbers.
What is the ones digit number in the product of the first 100 numbers?
Zero.
Name a 10 digit Number such that the first digit on the left tells how many 0 are in the numbers?
1234567890
What is the smallest three-digit number divisible by the first three prime numbers and the first three composite numbers?
The smallest three-digit number divisible by the first three prime numbers (2, 3, and 5) and the first three composite numbers (4, 6, and 8) is 120.
How many 5 digit combos in 30 numbers?
The answer will depend on how many digits there are in each of the 30 numbers. If the 30 numbers are all 6-digit numbers then the answer is NONE! If the 30 numbers are the first 30 counting numbers then there are 126 combinations of five 1-digit numbers, 1764 combinations of three 1-digit numbers and one 2-digit number, and 1710 combinations of one 1-digit number and two 2-digit numbers. That makes a total of 3600 5-digit combinations.
How many three digit numbers can be formed that do not contain the number zero and no number can repeat?
Let's look at this digit-by-digit: The first digit can be any number 1-9: 9 choices The second digit can be any number 1-9 except the one that the first digit is: 8 choices The third digit can be any number 1-9 except the ones chosen by the first and second digits: 7 choices 9*8*7 = 504 total numbers
How many different 7-digit telephone members are possible if the first digit can not be zero and no digit repeat?
There are 10 possible numbers that can be chosen. Since the first digit can't be 0, there are 9 selections for the first digit. The second number can include a 0, but can't include the first number chosen, so there are 9 selections for the second digit. Then there are 8 digits for the next number, 7 digits for the next number, and so on. Total telephone numbers are: 9*9*8*7*6*5*4 = 544320 phone numbers.
How many 3 digit number are such that their first digit equals the sum of the last two digit?
There are 54 such numbers.There are 54 such numbers.There are 54 such numbers.There are 54 such numbers.
What is the smallest three digit number divisible by the first three prime number and the first number three composite numbers?
120
What is the least product possible when you multiply a 1 digit number greater than 0 by a 2 digit number?
10 because 10 is the first 2 digit number out of all numbers.
