Answer Choices
115
120
124
173
Explanation for Question 26 From the Math (Calc) Section on the Official Sat Practice Test 1
So here in question number 26, we're talking about pear trees and type areas. 2 Pear trees produce 20% more pairs than type B pear trees. 3 And we want to know, based on this observation, if type a trees produce 4 144 pairs, how many, the type B trees produce, 5 right? So let's try to turn this observation that a produce 20% more than 6 B into an equation, 7 right? So if I have a, 8 a is producing more than being right, it's producing 20% more. 9 So you might be tempted to say, okay, a times 0.02 will give me 10 B, but that's not going to work. Right. 11 Because that would make a smaller than B. 12 So what I really need to do is show that a produces 13 B plus 0.02 times 14 B, right? So I'm starting with my baseline of being that I'm getting 20% 15 more of that B. So in other words, 16 I can say that a is equal to 1.02 V. 17 Cause I can combine like terms. I have to be variables one with a 18 coefficient of one and one with a 0.02 and one plus 0.02 is 1.02. 19 So I can write an equation like this, that shows the a is producing 20 one, all of the pairs from B plus 20% more of the pairs from 21 B. And now later in the question, they tell us that a producer's 144 22 pairs. So I can plug that into my equation. 23 I now have 1 44 is equal to 1.02 B and I need to solve 24 for B. So all I need to do here is divide by 1.02, 25 cause that's all I have this attached to B. Now, 26 if I do one point 44 times 1.0, 27 it should not be zero two. This should just be two, 28 right? For 20%. So let's fix that real quick. 29 All right. So we need to do 1 44 divided by 1.2 and that'll give 30 us 120. So B is equal to 120, 31 which is answer choice P so our best answer has to be B.