What idiot assigned this problem?
My younger brother got an assignment and asked me for help.
Find all the four-digit numbers whose sum of all digits lies on the interval <12,16>.
It's hardly a problem to solve it numerically, but does anybody know an analytical solution?
This is a truly stupid problem at any level of mathematics!
It does not ask "how many" . . . it says Find.
. . It wants a list of the numbers!
For a digital sum of 12, there are over 300 such numbers.
Does the teacher want to see all of them?