Question: In San Diego Zoo, the lion consumes 25 kilograms of meat, and the tiger consumes 20 kilograms of meat per day. If they have 90 kilograms of meat, how many days will the meats last?
Answer: Step-by-step reasoning process: The lion and tiger's daily consumption of meat is 25 + 20 = 45 kilograms. Therefore, their supply of meat will last for 90 / 45 = 2 days.
So the answer is 2.

Question: George is about to celebrate his 25th birthday. Since his 15th birthday, he's been given a special $1 bill from his parents. They told him that on his 25th birthday, for every bill he still has, they will give him $1.5 in exchange. He spent 20% of his special bills. How much will he receive from his parents when he exchanges them?
Answer: Step-by-step reasoning process: He received 10 special bills because 25 - 15 = 10. He has 80% of them left because 100 - 20 = 80. He has 8 left because 10 x .8 = 8. His parents will give her $12 for them because 8 x 1.5 = 12.
So the answer is 12.

Question: John buys 4 pounds of beef. He uses all but 1 pound in soup. He uses twice as many pounds of vegetables as beef. How many pounds of vegetables did he use?
Answer: Step-by-step reasoning process: He used 4 - 1 = 3 pounds of beef. So he used 3 * 2 = 6 pounds of vegetables.
So the answer is 6.

Question: Brennan was researching his school project and had to download files from the internet to his computer to use for reference. After downloading 800 files, he deleted 70% of them because they were not helpful. He downloaded 400 more files but again realized that 3/5 of them were irrelevant. How many valuable files was he left with after deleting the unrelated files he downloaded in the second round?
Answer:
Step-by-step reasoning process: The number of non - valuable files Brennan downloaded in the first round is 70 / 100 * 800 = 560 files. The number of valuable files Brennan downloaded in the first round is 800 - 560 = 240. When he downloaded 400 new files, there were 3 / 5 * 400 = 240 non - useful files, which he deleted again. The total number of valuable files he downloaded in the second round is 400 - 240 = 160. To write his research, Brennan had 160 + 240 = 400 useful files to reference to write his research.
So the answer is 400.