Business and residential areas is 30 mph
Generally around 25MPH depending on the area, this will vary (usually between 15 and 35 MPH), but the mean residential speed limit is 25MPH. The prima facie speed limit for residential areas is 25 miles per hour, and most residential areas reinforce this limit with posted signs displaying the 25-mile per hour limit. However, some roadways in sparsely populated residential areas may be posted at the higher limit of 35 miles per hour. Unless you observe a sign that indicates otherwise, you should adhere to the prima facie limit.
Whatever the posted speed limit is.
The speed limit for/in residential areas is always 25mph unless otherwise stated, such as, you see a sign that says"15MPH Speed limit". Also school zones(areas near a school) are likely to have a sign saying something like "Speed Limit 15MPH while flashing", this means when the yellow lights on or right above the sign are flashing the speed limit is whatever it says. The only ways for the "while flashing" speed limit is to change(or be "ignored") is if there are police officers and/or crossing guards there directing traffic or if there is a car crash(this would depend on where it happened, how bad the car crash is, how many cars, and any danger zones(for example a car in flames) ).
It depends. If it isn't a cop hotspot then it is at your discretion. I can't tell you how fast to drive. Only you know how fast you can go confidently. Also it is common courtesy to go 1 under the limit in residential areas.
The speed limit is 49.7 (50) miles per hour.