<p>I need help with a few math problems that are in my SAT packet.
I just want to how to solve these problems mathematically, besides guess and check.
Thank you very much.</p>
<li>If 60 percent of x is equal to y percent of 40, where y > 0, what is the value of x/y</li>
<li>Forty percent of the songs played on a certain mp3 player are 4 minutes long, thirty-five percent of the songs are 3 minutes long, and twenty-five percent of the songs are 2 minutes long. What is the average (arithmetic mean) number of minutes per song played on this mp3 player?</li>
<li>The number of registered voters in City X increased by 18% over last year. There are now 12,803 registered voters. How many registered voters were there last year?</li>