The answer is B:40 hours. You take 200 divided by 20 to get 10 (the amount of 20 page sections he needs to read) and then multiply 10 by 4 (the speed he reads).
Henry swims at 1.6 laps per minute, Larry swims at 1.8 laps per minute. Larry swims faster
Find 28/70 and then mult. the result by 100%.
Using a calculator, 28/70 = 0.4. Multiplying this result by 100%, we get 40%.
