John drove at 20 mph for 30 minutes, and then he drove back home at 10 mph. What was his average speed for the entire trip?

Owen can read a 100 page book, which had 500 words per page. It took him 2 hours less time than it takes him to read a 150 page book with 600 words per page. How long would it take him to read a 400 page book which had 400 words per page?

Geoge the Monkey can run at a speed of 12 mph. Hazel can walk at a rate of 4 mph, and Henrietta can walk at a rate of 2 mph.

George is standing halfway between Hazel and Henrietta, who are 1,320 feet apart, and begin walking toward each other.

At the moment they begin walking, George begins running toward Hazel. When he reaches her, he turns around and runs to Henrietta. Upon reaching her, he turns around again, and continues on like this, until the two girls meet, and he is sandwiched between them.

How far did George run?

Marco walks a certain distance at a certain speed (measured in miles per hour), and then returns over the same distance at a speed one mph less than his original walking speed. He took a total of 35 hours. If, instead of slowing down for his return journey, he had sped up by one mph, his journey would have taken 27 hours. How far did he walk?

A clock adjusts its timing each night by contacting a satellite at 2:00 AM to find out the official standard time. Since it has a mechanical action with physical minute, second and hour hands, if the clock finds out it is out of sync, it will move at 12 times normal speed in order to "catch up" with the actual time. (If it is ahead of the correct time, it will still move forward, until it wraps around to the correct time.)

In the fall, when Daylight Savings Time happens, at 2:00 the satellite tells the clock that it is actually 1:00. Thus, the clock has to move forward at high speed until it wraps around to the correct time.

How long will it take the clock to be displaying the correct time again?