The students at mill middle school held a class election. alyssa and megan were the only two candidates running for class president. megan received 21 votes and alyssa received 29 votes. what percent of the votes did alyssa receive?

In this problem, you add 21 and 29. That results in 50 and you can either:
1. Divide 29 by 50 and multiply 100. 29/50= .58 * 100= 58% or
2. Since percentage is based on 100 and the denominator is 50, multiply the top and bottom by 2 like so.
29 x 2 =  58
---    --      so that makes your percentage 58.
50 x 2 = 100

Hope this is clear enough.