Need help with math practice problem

Test Preparation SAT Preparation
1

<p>This is problem 20 from section 2 of practice test two in the College Board SAT Study Guide. </p>

<p>At the beach, a rectangular swimming area with dimension x and y meters and a total area of 4000 square meters is marked off on three sides with rope, as shown above (sorry, I can't draw it in), and bounded on the fourth side by the beach. Additionally, rope is used to divide the area into three smaller rectangular sections. In terms of y, what is the total length, in meters, of the rope that is needed both to bound the three sides of the area and to divide it into sections?</p>

<p>As far as the picture of the swimming area, I can't draw it but it looks like rectangle divided into 3 equal sections. x is the shorter length and y is the longer one. The beach is a y length boundary. </p>

<p>I know the answers is y + 16000/y but I can't work it out as to why. I would appreciate an explanation, it's the only one I missed and it's driving me crazy.</p>

2

<p>You could do this with algebra. But it is also easy to make up numbers:</p>

<p>Choose an x and a y that makes the area 4000. [I used x = 400, y = 10]</p>

<p>Then count up the length of all your ropes. [With my numbers, its 10 + 400 + 400+400+400]</p>

<p>Then put your made up numbers into the answer choices…pick the one that matches your answer (the one you got by making up numbers).</p>

<p>Even for students who are fluent in algebra, this method is very useful.</p>