Answer this question:Angela wants to check her math homework answers with her friends, but some of them aren't done yet. Out of 20 problems, Martha has finished 2, Jenna has finished four times the number Martha did minus 2, and Mark has finished half the number Jenna did. If none of the friends worked on any of the same problems, how many problems have no one but Angela finished?
Four times the number of problems Martha answered is 4 x 2 = 8. So, Jenna answered 8 - 2 = 6 problems. The number of problems Mark answered is 6 / 2 = 3. The total number of problems Martha, Jenna, and Mark answered is 2 + 6 + 3 = 11. So, this means Angela was able to answer 20 - 11 = 9 problems.
The answer is 9.

Answer this question:I have purchased 5 blue apples at the store. Suppose my neighbor gives me twice as many yellow apples as I have blue ones, and then I give my son 1/5 of the total number of apples; how many apples do I have now?
The number of blue apples is 5, and if you receive twice as many yellow apples as the number of blue apples, there will be 5 * 2 = 10 yellow apples. After receiving the yellow apples, you now have 10 yellow apples + 5 blue apples = 15 apples. When you give 1 / 5 of the total number of apples to the son, you part with 1 / 5 * 15 = 3 apples. The total number of apples remaining is 15 - 3 = 12 apples.
The answer is 12.

Answer this question:The total number of books on four shelves, with 400 books each, is the same as the distance in miles that Karen bikes back to her home from the library. Calculate the total distance that Karen covers if she bikes from her home to the library and back.
If each shelf has 400 books, then the four shelves have 4 * 400 = 1600 books. Since the total number of books on the shelves is the same as the distance that Karen bikes back home, biking to and from the library takes 1600 + 1600 = 3200 miles.
The answer is 3200.

Answer this question:Skyler is a composer. He wrote 25 hit songs that made it on the top 10 charts; ten more songs that made it on the top 100 charts than the hit songs; 5 fewer songs than the hit songs that were never released. How many songs did Skyler write in all?
Skyler wrote 25 + 10 = 35 songs that made it on the top 100. He wrote 25 - 5 = 20 songs that were never released. So, Skyler wrote a total of 25 + 35 + 20 = 80 songs.
The answer is 80.