Question: Brian likes to read books. He read one book that had 20 chapters, two books that had 15 chapters each, and one book that had half the chapters of the three previous books put together. How many chapters of books did Brian read?
Answer: Brian read two books with 15 chapters, so he read 2 * 15 = 30 chapters. He also read a book with 20 chapters, bringing the total for the first three to 30 + 20 = 50 chapters. He then read a book with half the chapters of his cumulative total so far, so it had 50 / 2 = 25 chapters. In total, he read 30 + 20 + 25 = 75 chapters. The answer is 75.

Question: Rocky boxed 190 fights in his career. 50 percent of his fights were knockouts, and 20 percent of the knockouts were in the first round. How many knockouts did Rocky have in the first round?
Answer: Knockouts:190(.50) = 95. First Round:95(.2) = 19. The answer is 19.

Question: Dina has 60 dolls. She has twice as many dolls as Ivy. 2/3 of Ivy's dolls are collectors editions. How many collectors edition dolls does Ivy have?
Answer: Ivy has 60 / 2 = 30 dolls. Ivy has 30 / 3 * 2 = 20 collectors edition dolls. The answer is 20.

Question: Ken can do 20 sit-ups without stopping. Nathan can do twice as many, and Bob can do half the number of Ken and Nathan's combined sit-ups. How many more sit-ups can Bob do compared to Ken?
Answer:
Nathan can do 20 x 2 = 40 sit ups. Ken and Nathan's combined number is 20 + 40 = 60 sit - ups. Bob can do 60 / 2 = 30 sit - ups. Bob can do 30 - 20 = 10 more sit - ups than Ken. The answer is 10.