139 is the answer.
How many different numbers can you make if you use the digits 1, 2, 3, 4 once each, in any order, and a times sign. For instance 31x24, or 2x413.
The sum of the digits of a three digit number is 12. If the hundreds digit is 3 times the tens digit and the tens digit is 1/2 the units digit, what is the tens digit of the number?
A number consists of four different digits where last digit is two times the first digit, second digit is two times the last digit and third digit at tens place is 3 less than the second digit. What is the difference of this four digit number and number formed by reversing its digit?