Explanation for Question 16 From the Math (Calc) Section on the 2019 May Sat
So for question 16, we need to use the chart and information above in 2 order to solve the question states, 3 the band was composed of freshmen, 4 sophomores, juniors, and seniors. 5 If 30% of the students in the band were juniors, 6 how many students were in the band? So the, 7 see how many students were juniors and in the band, 8 we need to go up to this chart at the top. 9 So let's find band and juniors. 10 And that brings us to this box right here, 11 which tells us that there were 18 juniors in the band. 12 So now that we have that information and we know that, 13 right? So not that we have that information, let's just write that down really 14 quick. So there were 18 juniors in the band, 15 and we know that those 18 juniors represent 30% of the students 16 in the band, which means that 18 over X X 17 representing the total number of students in the band, 18 which is what we're solving for is equal to 30, 19 over 100, 20 because the fraction of juniors out of the whole body student body that 21 was in the band is equal to 30% or 30, 22 over a hundred. So with this information, 23 we can cross multiply. So we have 30 X is equal to a hundred 24 times 18, which gives us 30 25 X 26 is equal to 1800. 27 And then finally we can divide both sides by 30 and we get X 28 is equal to 60. And so from that, 29 we know that the answer is D.