How many squares are in this picture?

An old auto is to drive a stretch of 2 miles, up and down a hill. Because the auto is so old, you cannot drive the first mile (the ascent) faster than 15 miles per hour.

How fast do you have to drive the second mile (going down the hill) in order to get an average speed of 30 miles per hour?
Riddle AnswerBelow are six discs stacked on a peg. The object is to reassemble the discs, one by one, in the same order on another peg, using the smallest number of moves. No larger disc can be placed on a smaller disc. How many moves will it take?

In a long, narrow chute there are 8 balls: 4 black ones on the left, and 4 white ones-slightly larger-on the right. In the middle of the chute there is a small niche that can hold 1 ball of either color. The chute’s right end has an opening large enough for a black but not a white ball.

Roll all the black balls out of the chute. You can’t pick them up from the chute.
Riddle AnswerThere are five squares formed by 12 matchsticks as shown in the figure. Can you remove just two matchsticks so that only two squares remain?
