Final answer:
Clara could type 8 sheets in 1.5 hours. A cyclist would take 3 hours at a speed of 25 km/h. It would take 18 minutes 45 seconds to walk home at 80 steps per minute. With nine friends, each would get 10 cookies.
Step-by-step explanation:
Clara can type 16 sheets of literature work in 3 hours. To find out how many sheets she could type in an hour and a half, we simply divide 16 by 3 to get the rate per hour: 16/3 sheets per hour. Then we multiply by 1.5 hours to get 8 sheets (Option D).
If a cyclist takes 2.5 hours to reach a city at a speed of 30 km/h, to find the time it takes at a speed of 25 km/h, we set up a proportion since time is inversely proportional to speed: 2.5 hours / 30 km/h = x hours / 25 km/h. Solving for x gives us 3 hours (Option C).
Walking at 60 steps per minute for 25 minutes, the total number of steps taken is 60 * 25. When walking at 80 steps per minute, to cover the same number of steps the time taken is (60 steps/minute * 25 minutes) / 80 steps/minute which equals 18 minutes 45 seconds (Option C).
When six friends each give a box of 15 cookies, total cookies exchanged are 6 * 15. If they were nine friends, the total number of cookies exchanged remains the same; however, each would get 90 / 9 which equals 10 cookies each (Option A).