You can put this solution on YOUR website! Uniform rates problem, and here, you first want to find the rate for one man. The rates of men working together are simply added.
If 8 men need 1 day to do the job of "prepare one book", then 1 man needs 8 times longer than 8 men.
The way you can show the uniform rate equation can be , the variables being Rate, time, job. Units need to be consistent. If r is the rate for 1 man, and n is the number of men working simultaneously, then you can write, .
Your example can take the process of (1) Find the one-man rate; (2) Setup the uniform rate equation according to and solve for n.