Mystery Number Help

Question

 This mystery number has four digits. No digit is used more than once. The smallest digit has the most value. The greatest digit has the least value. There is a 4 in the hundredths place. The number rounds to 12. What is the mystery number?

Answer 1

Answer: 12.34

Explanation:

Four digit number _ _ _ _ . Well there are a few hints given in the text for instance the text states that the number ROUNDS to 12. Therefore, the number has to be 11. something 5 or greater or 12. something less than 5. For example, 11.67 would round UP to 12 and 12.31 would round DOWN to 12. So now we know our 4 digit number is a decimal we also know that the first number has to be a one in order to round to twelve the first 2 digits are either 11 or 12.

So, 1_._ _ . Well no number can be repeated more than once so it can't be 11 because you would use the number 1 twice. So now we know 12. _ _ . Another clue is that 4 is in the hundredths place (the second number after the decimal... the first number is the tenths place). So, 12. _ 4. As we discussed before this number has to round down to 12 so the missing number has to be less than 5. Well it can't be 4 we already used a 4, it can't be 1 or 2 either because we already used those. Therefore, the final missing number is 3. 12.34