a.What two-digit number equals the product of units' digit by the factorial of tens' digit?
b. What if a non-decimal system (base below ten) were allowed?

(In reply to beyond base 10, analytical solution by Daniel)

You have to pay attention that  both x and y are less than b and b<10. 

Posted by Ady TZIDON on 2018-06-01 04:14:13