If 2 crew members work on a project that requires 80 hours each, how many 8-hour days will it take for 5 crew members to complete the project?

To determine how many 8-hour days it will take for 5 crew members to complete a project that requires a total of 160 hours of work (since 2 crew members each working 80 hours amounts to 160 hours), you can calculate the total available work hours with the 5 crew members.

Each crew member works 8 hours in a day. Thus, in one 8-hour day, 5 crew members collectively produce:

5 crew members x 8 hours = 40 total hours of work per day.

Now, to find out how many days it will take to complete the 160 hours of work required, divide the total project hours by the daily output:

160 total hours / 40 hours per day = 4 days.

This calculation shows that with 5 crew members working 8-hour days, they will complete the project in 4 days, which justifies the choice as the correct answer.