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?
let the two digit number by xy and the base b.
Then we require
solving for b we get
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 2018-05-31 23:55:17