Explanation for Question 8 From the Math (Calc) Section on the Official Sat Practice Test 9
Question eight asks us the line graft in the X, 2 Y plane below models. The total cost in dollars for a cab ride. 3 Why in a certain city, during non-peak hours, 4 based on the number of miles traveled X. 5 So the number of miles traveled is what corresponds to X and the total 6 cost is Y according to the graph, 7 what is the cost for each additional mile traveled in dollars of a cab 8 ride? So let's look at this graph and see what it's telling us. 9 It's flooding distance traveled versus cost. 10 So we can see that at zero miles traveled, 11 there's a base fee of $3. 12 It's asking us the cost for each additional mile traveled. 13 So we want to find how much are we being charged per mile. 14 So that is just finding the slope of the line. 15 And we can take any two random points for this, 16 but I'm going to pick 0.03 and 0.15, 17 and to find the slope of the line, we just need to do Y 18 two minus Y. One is equal or Y two minus Y one over X, 19 two minutes, X one. If you get five minus three, 20 over one minus zero, we get two over one, 21 which is equal to two. And we also could have seen that by just 22 doing rise over run. We see that it climbs to, 23 and the Y direction for movement of one in the X. 24 So based off of that, the units on two, 25 on our slope, our dollars per mile. 26 And that's exactly what the question is asking. So we can pick a $2.