Why should SoloLearn approve questions that really can't be figured out in a short period of time?

Question

For example, I stumbled upon this question in a JavaScript challenge here on SoloLearn by alvaro mesa. The answer to the question could be quite simple but the time allocated to get the right answer here on SoloLearn can never be enough. I think SoloLearn should have a better review for such questions or what do you think?
var a = 2;
var b = 3;
var c = 5;
var d = a + b;
var e = ++b;
var x = c % 2;
alert(d % e - x);

Answer 1

SoloLearn is about coding