Now if you say that last 2 digits of x gonna be only 50 or 00, then you'll miss a lot of cases. That's why your answer would be wrong if there were 570 students. X will be equal to 225.
We can clearly see that 152 and 100 not co-prime. So deduce the ratio in the lowest form.
x can be any multiple of 25. So last 2 digits of x can be 25,50,75 or 00.
nick1816 thanks for the feedback. However, as long as the total number of students is less than 630, the answer to this question per the reasoning provided in my solution will still be 303. Why? The test criterion is 2.52x≤the total number of students.
So 2.52x≤570 Hence x≤226. Possible values of x are 50,100,150,200,250,300,350, etc. Clearly, for the minimum possible value of students who do not participate in any of the 3 events, x must be 200. Still, any value of x greater than 200 will mean that the total number of students will still be more than 570, hence 250 and above are still not applicable. Unless I don't understand the point you're making the solution provided above should still work.
I only relied on numbers theory to come up with the possible values of x to have their last two digits to be either 00 or 50(implying x is a multiple of 50) since 1.52*x must be an integer.
eakabuah
Alternatively
Let x represent the number who participated in exactly 1 event, y represent the number who participated in exactly 2 events, and z represent the number who participated in all three events.
Then y+z=1.52x -------(1)
Since the total number of students in the school is 510, then the last two digits of x is either 00 or 50. In other words, x must be a multiple of 50.
Possible values of x are: 50,100,150, and 200. Note that when x=250, the total number of students exceeds 510. i.e. (1.52+1)*250=630 and 2.52x≤510. Hence x cannot exceed 200.
From the information given, we need the number of students who did not participate in any of the 3 events to be minimum. Hence, x must be 200.
y+z=1.52*200 = 304
But from the second information provided above, y ≥ 1.
Hence z is maximum when y=1.
z=304-1=303
The answer is C.