Explanation for Question 16 From the Math (Calc) Section on the 2017 May Sat
So question 16 says those are conferencey of a mother elephant, 2 circular footprint is four times as a conference of a baby elephant circular footprint. 3 What is the ratio of the height of the mother to the height of 4 the baby? I wrote the equation from above here. 5 So we have it. We're going to be playing a little bit here with 6 ratios comparing, um, 7 and particularly when we're comparing the circumference. 8 So we know that that's the C right there. We're just going to be 9 plugging in some numbers to see their relationship. 10 So if we see that it's four times larger than mothers, 11 um, circumference, we can say the baby elephants, 12 um, circumference, we can just call it C. 13 And if that, see the mother elephants would be foresee because it's four 14 times larger. So now let's plug that into our equation to see how it 15 affects the height. So for the baby elephant, 16 um, we're going to have H equals three and see again, 17 it's just, um, let's see. 18 Now for the mother elephant, 19 we're going to have H equals three, 20 but when the circumference is actually foresee, 21 so you're place that with foresee, let's multiply that out 22 to simplify. We have H equals 12 C for 23 the mother and H equals three C, 24 let me circle those so that we know where our final, 25 our final equations are. 26 So we know the height for the baby is three times a variable 27 and the height for the mother is 12 times a variable. 28 So we want to know how many times larger is the height of the 29 mother than the baby. And we have the ratio of 12 30 to three that can be simplified to four to 31 one. If that's kind of confusing to you, 32 just remember very, um, ratios are essentially fractions. 33 So that's the same thing as saying 12 to three. 34 And if you just divide that and simplify that you get four to one, 35 which is C.