a number rounds off to 4000.The digit in the hundreds place is twice the digit in the tens place.The sum of the digits is 12.The number uses only two different digits.Find the number.

Answer 1

the number is between

3500 and 4500

So, now we start working with the info. The hundreds digit is even, so

363x
384x
400x
421x
442x

If the digits add to 12, that means we can have only

3630
4008
4215
4422

So, what do you think?