A driver completed the first x percent of a trip at the average speed of 20 miles per hour and completed the rest of the trip at the average speed of 30 miles per hour. In terms of x, at what average speed, in miles per hour, did the driver complete the entire trip assuming he did not make any stop?
Chris and James are cycling in the same direction, on the same course. At 3:00 pm., Chris, who is peddling at 20 miles per hour, crosses a bridge. One hour later, James passes the same bridge. James is traveling at 24 miles per hour. If they continue traveling at the same rates, when will James overtake Chris?
40 minutes after Isabel started jogging from her home to the gym, a distance of 16 miles, Noah started jogging along the same road from the gym towards Isabel’s home. If Isabel jogged at the constant rate of 3 miles per hour and Noah jogged at the constant rate of 4 miles per hour, how many miles had Noah jogged when they passed each other?