posted by Sam .
If 5 fishermen catch 5 fish in 5 minutes, how many minutes will it take 50 fishermen to catch 50 fish?
If 5 fishermen catch 5 fish in 5 minutes, then the average time it takes each fisherman is 5 minutes to catch one fish. It will take 50 fishermen 5 minutes to catch 50 fish -- at the rate of 1 fish per man per 5 minutes.
You're reasoning is absolutely correct.
"If 5 fishermen catch 5 fish in 5 minutes, how many minutes will it take 50 fishermen to catch 50 fish?"
There are two separate, but related, items to look at: the expected number of fish each person caught and the expected time it took them to catch a fish.
We're told that 5 people caught 5 fish, but not how many each caught. One person could've caught all 5! However, the expected number of fish each caught is the simple average, or 5 fish per 5 fishermen = 1 fish. The expected time period is the same time interval for each person. The answer to the question is a constant time for each fishermen to catch one fish, or 5 minutes. If the question had been e.g., how long would it take 50 fishermen to catch 100 fish?, then since it takes each 5min/fish, it should take 10min.