[50.] A sets out from a place and travels 5 miles an hour. B sets out 4½ hours after A and travels in the same direction 3 miles in the first hour, 3½ miles the second hour, 4 miles the third hour, and so on. In how many hours will B overtake A?
OFTEN ASKED.
[51.] What is the difference between 4 square miles and 4 miles square?
TO TELL THE NUMBER THOUGHT OF ON A CLOCK.
Ask a person to think of any number on the dial of a clock; you then point, promiscuously at the various numbers, telling the person to add the number of times you point to the number he thought of, and when the total reaches 20, you will be pointing at the number he selected.
For instance, suppose he selected the number 5. You point indifferently 7 times at the various numbers, but the 8th time your pointer must be at XII., his addition will then be 13 (for 5 and 8 added equal 13), the next at XI., his addition then 14, next at X., and so on. When he calls 20, you will be pointing at the number he thought of—5.