Please answer at least one of them.
1)Four painters can paint a room in 6 hours. How long will it take three painters to paint the same room?
2)It takes three identical water pumps 8 hours to fill a pool. How long would it take four of the same pumps to fill the pool?
3)Of 400 trees in a park, 280 are deciduous. What is the ratio of the deciduous trees to all trees in the park?