If you apply a bit of logic, the solution to this problem is very simple. The trick is to clearly understand the two conditions given:
(1) "1 out of every 5 students who applied for the scholarship got it".
This means if 5 applied, 1 got it and 4 didn't; if 10 applied, 2 got it and 8 didn't; and so on.
The second take-away is: the greater the number of students who applied for and got the scholarship, the greater the number who applied and didn't. So if we can find the
greatest number of students who could have got the scholarship (subject to the constraint imposed by the 2nd condition), we will have our answer simply by multiplying that number by 4. Which brings us to the 2nd condition:
(2) "The ratio of the number of students who got the scholarship to the number of students who didn't is NOT MORE THAN 1:9".
This means that the greatest number of students who could have got the scholarship is 6 because any number more than that would not be in compliance with the ratio of = to or <1:9 [e.g. if 7 students got the scholarship, 63 students (or more) would have to be unsuccessful in order to comply with the ratio which means the total number of
students would have to be 70 or more].
So, given the above conditions, if the greatest number of students who could have got the scholarship is 6, the maximum number of students who applied for but did not get it must be 6 x 4=24.