[Video] Q10: At which of the following air temperatures will the speed of a sound wave be closest to 1,000 feet per second?

Explanation for Question 10 From the Math (Calc) Section on the Official Sat Practice Test 1

So looking at question 10, it wants to know which of the following air 2 temperatures. So we're solving for a T will be will 3 the speed of sound be closest to 1000, 4 right? So here they've told us that a is equal to 1000 because the 5 speed of sound is what a is, and we want to solve for T. 6 So let's go back up to our equation. It says 1 0 5, 2 plus 1.08 7 T is equal to a right. 8 And we know that our a is 1000. 9 So 1 0 5, 2 plus 1.08 T is 10 equal to 1000. And now I'm just going to solve for T I can 11 start by subtracting 1 0 5, 2 from both sides because that'll help me get tea 12 on its own. This one's 0 5, 2 is in the way. 13 So I'll start by subtracting that. And I get 1.08 T is equal 14 to negative 52 now to finally get T on its 15 own, I need to get rid of the 1.08. 16 And I do that by dividing it, right, because the 1.08 is in the 17 numerator. So to get rid of it, I have to put a 1.08 in 18 the denominator, which is the same as dividing. 19 So I do that to both sides. We take our calculator, 20 we plug it in negative 52 divided by 1.08, 21 and we'll get a value of about negative 48, 22 which leads us to choose answer choice B.