Explanation for Question 21 From the Math (Calc) Section on the 2019 October Sat
And question number 21. We're told that there's a certain elephant that weighs 200 2 pounds at birth. It's when they start their life, 3 they weigh 200 pounds and they gain more than two, 4 but less than three pounds during the first year. 5 Right? So there's kind of a minimum, right? 6 They're going to gain at least two pounds, 7 but they're going to knocking more than three pounds every year during the 8 first year, um, 9 per day. So these are for pounds gained every day. 10 And now if we're talking about the first year, right, 11 then we know that there's 365 days in a year. 12 And if that elephant gains the minimum, if they gain two pounds for each 13 of that 365, then we can do two times 365 and our 14 calculators and we get 730, 15 right? So there's a possibility that they gained 730 and that's on the low 16 end, but there's also a possibility that they gained the most that they could 17 get. 18 Right. And that would be if they gained three pounds per day, 19 if you do three times, 365 and your calculator you'll get 1095, 20 right? And so you can see now that at least the minimum they will 21 gain in that year is 730 pounds. 22 But at most the maximum that they could possibly gain is 1095 pounds. 23 And so maybe you chose answer choice C because you see those numbers there. 24 But what we need to remember is the actual pounds of the elephant, 25 right? And that elephant started with 200 pounds. 26 So what we really need to be doing here is 200 plus seven 30 27 and 200 plus 1095. 28 And that's going to give us 930 here and 29 1000, 295 here. And so our best answer is going to be D 30 right, because the weight of the elephant has to be more than nine 30 31 because elephant will be gaining more than two pounds, 32 but it must be less than 1, 2, 9, 5, 33 because the elephant has to also be gaining less than three pounds. 34 And so that leads us to choose answer choice D.