<p>Anyone have the explanation to this test?
I have 3 math questions to ask:
1) There are 25 trays on a table. Each tray contains a cup only, a plate only, or both a cup and a plate. If 15 of the trays contain cups and 21 of the trays contain plates, how many contain both a cup and a plate?</p>
<p>2) What's the product of the smallest prime number that is greater than 50 and the greatest prime number that less than 50?</p>
<p>3) PRQS is a rectangle. T is a point on PS so that PT = 2/5 PS. Draw a line from T to R. The triangle RST has an area of 7. What's the area of PRQS?</p>
<ol>
<li>11 trays contain both a cup and a plate.</li>
</ol>
<p>15 (trays with cups) + 21 (trays with plates) = 36 trays
36 - 25 = 11</p>
<p>11 trays must have both a cup and a plate if there are 25 trays.</p>
<ol>
<li>The area of PQRS is 23.3333~</li>
</ol>
<p>If triangle RST has an area of 7, then the bh/2 = 7. So the base and height can be 2 and 7, 1 and 14, etc. Lets take 1 and 14 to make things easy. Line segment TS = 1, and line segment SR = 14. Since we’ve set 14 as the base, we now have one side of the rectangle. Now we just have to get the other side. </p>
<p>If PT = 2/5 PS, then TS must be equal to 3/5 PS. If PT = 2/5 PS and TS = 3/5 PS then PT = 2/3 TS. Since TS = 1, PT = 2/3. 1 + 2/3 gives us our second side, 1.3333~ (1 2/3). </p>