Hi! I'm new here...and Math is actually my weak subject, it'll be awesome if you could help me answer these questions. Pretty please? (If the rationale will be included--will appreciate it more!)

1. A pipe can alone fill a tank in 5 hours, while a drain can do the contrary in 12 hours. How long would it take the pipe to fill the tank if the drain was simultaneously opened during the duration of the filling job and if the tank were entirely emptied at the start?

2. A 24-foot ladder just reaches the sill of a window that is 12 feet above ground level. What angle of measure is the ladder inclined?

3. A man left 1/2 of his state to his wife, 1/8 to his daughter, and the remainder, an amount of 30, 000 to his son. How much was the entire estate?

4. In a particular 30day month, records show that there is more than 1cm of rain in 2 days, some rain but less than 1cm on 5 days and no rain on 23 days. If a day is chosen at random, what is the probability that it rained on that day?

5. A license plate consists of 3 letters and 3 numbers, where the 1st number can't be zero. What is the probability that a car's license plate is greater than 400?