Pick a 3-digit positive integer with all three digits different. Reverse the dig
ID: 1808409 • Letter: P
Question
Pick a 3-digit positive integer with all three digits different. Reverse the digits to get another 3-digit number. Subtract the smaller number from the larger to get another positive number. If the difference is less than 100, insert leading zeros so you have three digits (e.g., 71 becomes 071). Reverse the digits of the difference and add it to the difference to get a final 3-digit number. Is this association a function? If the association is not a function, draw a frowning face as your answer. If the association is a function, what are its domain, its codomain, and its range?Explanation / Answer
To get the greatest difference, we want to subtract asmall number from a large one, so we will need thedigit 9 and the digit 1, in order to make a number inthe 100’s and a number in the 900’s. The large numberwill look like 9N1 and the small number will look like1N9, where N is a digit from 2 to 8. You will find that,no matter what you make N, the difference is 792.