Explanation for Question 27 From the Math (Calc) Section on the 2017 May Sat
Question 27 says assemble of sea water is 3.5% salt 2 by mask and contains a thousand grams of salt, 3 which of the following is closest to the mass in grams of the sample 4 of seawater. So what we're trying to find is the sample of seawater, 5 and we can set up kind of like an equation stash proportion to, 6 um, understand how, um, 7 how many grams is the sample of seawater. 8 So if they tell us that it's 3.5% 9 salt by mass, let's change this person to a decimal to change into 10 a decimal. All you do is you move your decimal 0.2 points 11 to the left. So we go on to, 12 we add our zeros of we're poured that empty, 13 um, dips, and we get 0.03, 14 five. So now let's write our equation. 15 Um, we can call the sample of seawater X and we know that 16 3.5% of X is a thousand. 17 So X times 0.035 18 is a thousand. So whatever he is he of 19 in a sentence, or you hear of, 20 you know, that's the most application. And here they tell us that 3.5% 21 of the seawater sample is a thousand. 22 So we know we multiply them. That's how, you know, you multiply and don't 23 divide and then you, 24 um, want to solve for X. So you divide both sides by 25 0.035, and it has a calculator section. 26 So you grab your calculator and you get your answer to 27 be somewhere around 28,571 28 dot.dot. And it asks for the closest answer choice, 29 which would be a 28,600.