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How many numbers are possible if the first digit can only be a one?
Wiki User
∙ 14y ago
Because the number of digits is not specified, an infinite amount of numbers can be so.
Wiki User
∙ 14y ago
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How many 4 digit numbers can be formed from the digits 12345?
The first digit can have 5 possible numbers, the second digit can have 4, the third 3, the fourth 2. 5
How many three digit numbers are there?
There are 900 three digit numbers. (99 - 1000) (# of possible numbers in the first position = 9) (# of possible numbers in the second position = 10) (# of possible numbers in the third position = 10) 9 *10 *10 = 900
How many 3 digit counting numbers are not multiples of 5?
There are 720 of them. The three digit counting numbers are 100-999. All multiples of 5 have their last digit as 0 or 5. There are 9 possible numbers {1-9} for the first digit, There are 10 possible numbers {0-9} for each of the first digits, There are 8 possible numbers {1-4, 6-9} for each of the first two digits, Making 9 x 10 x 8 = 720 possible 3 digit counting numbers not multiples of 5.
How many three-digit area codes are possible if the first digit cannot be a 0?
There are 900 possible three-digit numbers not beginning with 0. (Note, however, that this question does not accurately describe the restrictions on numbers that can be used as area codes.)
How many numbers are there between 100 and 999 in which all three digit numbers are different?
There are 9 possible numbers for the first digit (one of {1, 2, ..., 9}); with 9 possible digits for the second digit (one of {0, 1, 2, ..., 9} which is not the first digit)); with 8 possible digits for the third digit (one of {0, 1, 2, ..., 9} less the 2 digits already chosen); This there are 9 × 9 × 8 = 648 such numbers.
How many different 7 digit phone numbers are possible if the first digit cannot be 0 or 1?
hi wazup hi wazup
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.
How many seven-digit telephone numbers are possible if the first two digits cannot be ones or zeros?
That makes:* 8 options for the first digit * 8 options for second digit * 10 options for the third digit * ... etc. Just multiply all the numbers together.
How many 3-digit numbers can be formed using 0123456789 when repetition is not allowed?
-123456786
How many three digit positive integers are square numbers?
102 = 100 which is the first possible three digit number that is a perfect square. 312 = 961 which is the last possible three digit number that is a perfect square. So there are 22 three digit positive numbers that are perfect squares.
How many different three digit numbers can you form using the digits 1 2 3 5 6 7 and 9 without repetition?
There are seven possible digits for the first digit and 6 digits for the second (minus one digit for the digit used as the first digit) and 5 options for the last digit (minus one again for the second digit) and then you just multiply them all together to get a total possible combination of 210 numbers that are possible.
How many four digit numbers are possible from the digit 0'1'2'3'4 numbers may be repeated?
625 if numbers can have leading 0s, 500 otherwise.
