a.What twodigit number equals the product of units' digit by the factorial of tens' digit?
b. What if a nondecimal system (base below ten) were allowed?
let the two digit number by xy and the base b.
Then we require
bx+y=y*x!
solving for b we get
b=y(x!1)/x
since gcd(x,x!1) then we need x to divide y
so for any two digits x,y where x divides y, selecting a base
b=y(x!1)/x would seem to make this work

Posted by Daniel
on 20180531 23:55:17 