Question: Tom buys 20 shares of a stock that costs $3 each. He sells 10 of those shares for $4 each. The rest of the shares end up doubling in value. How much profit does he make?
Answer with step-by-step thinking: He spends 3 * 20 = $60 on the shares. He sells 10 for 10 * 4 = $40. He sells the other 20 - 10 = 10 for a higher valuation. Their price was 3 * 2 = $6. So he got 10 * 6 = $60 from those. So in total, he got 60 + 40 = $100. So his profit was 100 - 60 = $40.
So the answer is 40.

Question: The Period 1 gym class has 5 fewer than twice as many students as in the Period 2 gym class. There are 11 students in the Period 1 gym class. How many are in the Period 2 gym class?
Answer with step-by-step thinking: Let x be the number of students in the Period 8 gym class. 2x - 5 = 11. 2x = 16. x = 8.
So the answer is 8.

Question: Sabrina went to the library and found a historical series novel called The Rangers Apprentice. There are 14 books in the series, and each book has 200 pages. She read four books in a month and half the number of books remaining in the second month. What's the total number of pages Sabrina has to read to finish the whole series?
Answer with step-by-step thinking:
The total number of pages in the series is 14 books * 200 pages / book = 2800 pages. Sabrina read 4 books * 200 pages / book = 800 pages in the first month. She still has 14 books - 4 books = 10 books after reading four books. In the second month, she read 1 / 2 * 10 books = 5 books. The total number of pages she read is 5 books * 200 pages / book = 1000 in the second month. In total, Sabrina 1000 pages + 800 pages = 1800 pages in two months. Sabrina has to read 2800 pages - 1800 pages = 1000 more pages to complete the total series.
So the answer is 1000.