Can someone please help with and please show workings

31. One pipe can drain a pool in 12 hours. Another pipe can drain the pool in 15 hours. How long does it take both pipes working together to drain the pool? 32. A faucet can fill a bathroom sink in 1 minute. The drain can empty the sink in 2 minutes. If both the faucet and drain are open, how long will it take to fill the sink? 33. A faucet can fill a bathtub in 6 %2 minutes. The drain can empty the tub in 8 % minutes. If both the faucet and drain are open, how long will it take to fill the bathtub? 34. An inlet pipe can fill a tank in 5 hours. An outlet pipe can empty the tank in 4 hours. If both pipes are open, can the tank be filled? Explain. 35. A delivery boy, working alone, can deliver all his goods in 6 hours. Another delivery boy, working alone, can deliver the same goods in 5 hours. How long will it take the boys to deliver all the goods working together? 36. A Space Shuttle astronaut can perform a certain experiment in 2 hours. Another Space Shuttle astronaut who is not as familiar with the experiment can perform it in 2 % hours. Working together, how long will it take both astronauts to perform the experiment? 37. On Tuesday and Wednesday of last week I left home for school at the same time. On Tuesday I drove 40 mph (miles per hour) on my way to school and arrived 3 minutes late. On Wednesday I drove 50 mph on my way to school and arrived 2 minutes early. How far do I live from work? 38. James' car is traveling 30 km/hr faster than Jody's car. During the time it takes Jody to go 250 km, James goes 420 km. Find their speeds. 39. A fully loaded train travels 16 km/hr slower than an empty train. The loaded train travels 440 km in the same time it takes the empty train to travel 600 km. Find the two speeds