How many different 3-digit identification tags can be made if the digits can be used more than once?
0-999 That's 1000 numbers. EDIT: Oops, I'll walk you through. 0-9 is 10 digits, you have to include the 0. 10 * 10 * 10 = 1000.
How many different 3 digit identification tags......?
Think of each digit individually If the first digit must be 5, there is only one choice. The second digit can be anything that's not yet been used. Only 9 are left since 5 has already been used. The third digit can be anything that's not yet used. 8 are left since 5 and whatever the second digit was has been used. Multiply all together to get the total count: 1 * 9 * 8 = 72
The difference of 2-digit number and the number obtained by reversing the digit is 27,find the difference between the digits of the 2-digit number?
Let the numbers be10x+y and 10y+x10x+y - (10y+x) = 27, or9x-9y = 27, orx-y=3x = y+3The numbers are 63 and 36 and the difference between the digits of the two numbers is 3.Suggested edits in last line:The numbers can be (14,41) or (25, 52) or (63,36). In case difference between the number & the number obtained after reversing the digits is 27.Difference in digits in each case is 3.Sanjay C.