2
$\begingroup$

I'm not sure if these types of questions are accepted here or not (I'm very sorry if it's not), but it would be great if anyone could explain me this.

Question: Using his bike, Daniel can complete a paper route in 20 minutes. Francisco, who walks the route, can complete it in 30 minutes. How long will it take the two boys to complete the route if they work together, one starting at each end of the route?

I have the answer: 12 minutes

But I don't understand the solution given in the book.

Can any of you explain how to solve this? Your help is highly appreciated.

3 Answers 3