Paul’s efficiency of doing a project is 40% more than that of Peter. If Peter takes 28 days to complete the project, how long will both of them working together take to complete the project?

A boat is travelling downstream and takes 15 hours to travel 30 km. If the speeds of the boat and the stream are in the ratio 2:1, what is the time taken by the boat to travel 10 km upstream?

A, B and C can together finish a project in 1 hour. A alone can finish it in 6 hours, C alone can finish it in 2 hours. How long will B take to finish the project working alone?

A 100 meter long train running at a speed of 54 kmph crosses a platform in 18 seconds. What is the length of the platform?

A and B together can complete a particular task in 4 days.If A alone can complete the same task in 6 days, how many days will B take to complete the task if he works alone ?