Explanation for Question 9 From the Math (Calc) Section on the 2019 October Sat
Now number nine, we're told that a tree has a height of six feet 2 when it's planted. There's the six and the equation above can be used to 3 find how many years. And it takes for the plant to reach a height 4 of the 14 feet. Right? So we're starting with the six and then something's 5 happening when we add two times the number of years, 6 and that will allow us to reach a height eventually of 14 feet. 7 And the question asks us, which of the following is the best interpretation of 8 two. And so we can see that two must have something to do with 9 the growth of the tree, right? Because six is our starting point. 10 The two allows us to grow, to reach the 14 and we're multiplying two 11 by every year. So it might be logical to think, 12 right, that this tree is going to grow by two feet every year. 13 And those two feet every year get added to the six feet that we 14 started with. So let's look at our answer choices and see which one says 15 that maybe in different words though, 16 right? So looking at a, it says it's the number of years it took 17 the tree to double its height. Now we know that it can't be a 18 because the number of years is represented by the variable N right. 19 So two, can't be the same thing as N. And is, 20 are yours too, as something else, you look at B it says the average 21 number of feet that the height that the tree grew for per year. 22 And so this should make some sense, right? Because the tree is going to 23 be growing about two feet per year. 24...