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How many seven digit numbers contain the number seven at least once?
To find the total number of seven-digit numbers that contain the number seven at least once, we can use the principle of complementary counting. There are a total of 9,999,999 seven-digit numbers in total. To find the number of seven-digit numbers that do not contain the number seven, we can count the number of choices for each digit (excluding seven), which is 9 choices for each digit. Therefore, there are 9^7 seven-digit numbers that do not contain the number seven. Subtracting this from the total number of seven-digit numbers gives us the number of seven-digit numbers that contain the number seven at least once.
How many combinations are there if there are seven numbers and you have to have a four number combination?
That dependsThat depends upon whether you are allowed to repeat numbers. If you are allowed to repeat, that means that all seven digits (say 1 through 7) can be used in each of the four positions of your combination, even if a digit has been used in another position. That means there are 7 x 7 x 7 x 7 = 74 = 2401 possible combinations for your lock. But if you are not allowed to repeat, that means that every time you pick a digit for one spot, there will be one less digit for the next, and one less for the next, and so on. So, the first number can have seven possibilities, the second can have six, the third can have five, and the last can have four possible digits. That means there are 7 x 6 x 5 x 4 = 840 possible combinations for your lock, only about a third as many.Check out the related link at MathsIsFun. It has very good information on this subject.* * * * *That is true for PERMUTATIONS, but not for combinations. In a combination, the order of digits does not matter so that 1234 is the same as 1342 or 4213 ext.As a result you have 7C4 = 7!/[4!*(7-4)!] = 7*6*5/(3*2*1) = 35 combinations - not 2401.Incidentally, nCr is the notation for the number of combinations of r objects taken from n objects - exactly what the question asked for.
What is the tens place of 734?
The digit in the tens place of 734 is the 3. The number is pronounced seven three four.
Why are phone numbers seven digits long?
Phone numbers are seven digits long in some countries but differing lengths in others. It purely depends upon what number of phone numbers the country needs .
How many seven digit numbers are there when 0 and 4 cannot be the leading number?
If the number can contain repeated digits, the answer is 800000. Without repetition, there are 483840.
Can a ten-digit phone number be a legitimate seven-digit number without the last three digits?
No, a 10-digit phone number that is missing the last three digits can not be a legitimate number. In order for a number to work, it must have 3 numbers for an area code and seven digits for the phone number itself. Some telemarketers are now using fake numbers to hide from the people they're calling.
How many different three digit whole number combinations can you make with 2 fives and 1 seven?
3. They are 755, 575 and 557.
How many seven digit numbers contain the number seven at least once?
To find the total number of seven-digit numbers that contain the number seven at least once, we can use the principle of complementary counting. There are a total of 9,999,999 seven-digit numbers in total. To find the number of seven-digit numbers that do not contain the number seven, we can count the number of choices for each digit (excluding seven), which is 9 choices for each digit. Therefore, there are 9^7 seven-digit numbers that do not contain the number seven. Subtracting this from the total number of seven-digit numbers gives us the number of seven-digit numbers that contain the number seven at least once.
What is a seven digit number that has a sum of 5?
1010111 1111100 1011101 and many more
How do you unlock Motorola krazer keybad?
You have to type in the password, (its the last four numbers of your seven digit phone number, that is unless you set the password to a different number)
How many four digit numbers are possible which do not contain 3 or 6?
The answer is 3,584. The first digit of the four-digit number can be one of seven figures: 1,2,4,5,7,8 or 9 (if it is 0, then you don't have a four-digit number!) Each of the remaining digits can be one of eight figures: 1,2,4,5,7,8,9 or 0. The number of possible combinations is therefore 7 x 8 x 8 x 8 = 3,584.
How many numbers are in a american phone number?
Three digit area code followed by seven digits for the subscribers number.
The unit digit number is 3 and seven times the sum of the digit is the number itself Find the number?
It is 63.
What is the greatest seven digit number?
the biggest number is 9999999.
What is the greatest seven-digit number using four different digits?
9,999,876 is the greatest seven-digit number using four different digits.
What is the greatest seven digit number with seven different digits?
9,876,543 is.
What is the smallest seven - digit number that you can form using the combination of numerals 1 and 2?
Assuming a seven digit whole number: 1,111,111. But if you have to use at least one (2) digit, then 1,111,112.
