There are 10 men spent 10 days finishing one project. If we need to finish the project by 5 days, how many more men do we need?

A.1
B.5
C.10
D.15
E.20
Choice E is wrong, i'm starting to think that choice B is the answer.

"how many MORE men do we need?"

is the answer 10?

Yes.

choice c is correct.

To find out how many more men are needed to finish the project in 5 days, we need to compare the number of man-days required to complete the project with the available man-days in 5 days.

In the original scenario, we have 10 men working for 10 days, which gives us a total of 10 men x 10 days = 100 man-days.

To complete the project in 5 days, we need to determine the number of man-days required per day. This can be calculated by dividing the total man-days (100) by the number of days (10), which gives us 100 man-days / 10 days = 10 man-days per day.

Next, we calculate the number of man-days needed in 5 days by multiplying the new target number of days (5) by the number of man-days required per day (10). This gives us 5 days x 10 man-days per day = 50 man-days.

Finally, to find out how many more men are needed, we divide the required number of man-days in 5 days (50) by the man-days one person can contribute in a day (10). This gives us 50 man-days / 10 man-days per person = 5 people.

Therefore, the correct answer is B. We need 5 more men to finish the project in 5 days.