Question 831561
This one sounds complicated haha.
Ok first thing, they say that the orbit of he moon around earth is circular, that means the moon will create a circle around the earth while it moves. Let's imagine the earth is a center of that circle. Then the distance of the moon from earth would be the radius of the circle, meaning 2.39*10^5 miles will be the radius. 
Now we need to find how many miles the moon needs to go to make a whole circle, that means the perimeter of the circle. 
C=2*pi*radius = 2*3.14*2.39*10^5 = 1500920 (this is approximately, because pi is not exactly 3.14, but you can still use this)
So the moon travels 1500920 miles and make a revolution in 27.3 days(given in the question) 
The speed will be 1500920miles/27.3days
27.3 days = 655.2 hours (1 day has 24 hours, just take 27.3 * 24) 
so you take 1500920 and then divide it by 655.2, you get 2290.781441
TA-DAH
The speed of the moon is approximately 2290.781 miles per hour :D