Explanation for Question 10 From the Math (Calc) Section on the 2018 March Sat
Question 10 says if the reservoirs capacity, 2 T years after 1928 was between 290,290 3 2000 acre feet, which of the following must be true. 4 So I'm going to start by setting up in inequality using this equation that 5 we got for the last problem. So 290,000 is 6 less than 300,000 whoops range, 7 a thousand minus 1,700 T, 8 which is less than 292,000. 9 So the first thing I'm going to do is subtract 300,000 from all three 10 sections. And that becomes negative 10,000 is less than 11 negative 1,700 T, 12 which is less than negative 8,000. 13 And then I'm going to divide all three sections by negative 1,700. 14 And since I'm dividing by a negative number, 15 all the inequalities are going to switch. 16 So when I do that, I get T is less than 4.71 17 and, or sorry, greater than 4.71 and less than 5.88. 18 And this range falls within T is greater than four and less 19 than six, which tells us that C is the correct answer.