I'm having trouble solving a puzzle in Swedish. I've translated it to English:
Two masons work on a project. One mason can complete the project alone in 8 hours, while the other can complete it alone in 10 hours. When they work together, they can finish the project in 5 hours, but they lay 30 fewer bricks per hour.
The question is: how many bricks do they lay together?
I'm not sure where to start, and I'm having trouble figuring out how to approach this problem. I did come across a solution that suggests the answer is 1200 bricks. According to this solution, if the number of bricks is X, then the first mason lays 0.1X bricks per hour, the second mason lays 0.125X bricks per hour, and together they lay 0.2X bricks per hour.
The equation to solve is 0.1X+0.125X-30=0.2X (-30 for the 30 fewer bricks per hour). The solution to this equation is X=1200.
However, I'm not sure if this solution is correct, and I'm not sure how to approach this problem on my own.