MARK (no relation)
0.3 miles
What a pity. He is a multi-millionaire.
PUMPS
4 hours
Pump A: 30 h/ V (V = volume of the water in the cellar), pump B: 20 h/ V, pump C: 15 h/ V, pump D: 10 h/ V. The pumping performances are expressed by reciprocal value formation into V/ h, then the deliveries of the pumps per hour can be added --> V/ 30 h + V/ 20 h + V/ 15 h + V/ 10 h = (after finding the common denominator considering the smallest multiple of the denominators = 60 h) --> 2V/ 60 h + 3V/ 60 h + 4V/ 60 h + 6V/ 60 h = 15V/ 60 h = (after reducing by 15) 1V/ 4 h (= 1/4 V/ h) --> (after reciprocal value formation): 4 h/ V , i. e. the 4 pumps had pumped out the cellar after 4 hours.
Mark:
TEDDY
24
One could set up a difficult equation with x = booty, in order to calculate, how much remains for the poor Teddy: (x - 1/2 x) - (x - 1/2 x) 2/3 - ( (x - 1/2 x) - (x - 1/2 x) 2/3) 3/4 = ? (remains for Teddy). However, it works more simply, according to the idea: Teddy will get: x 1/2 1/3 1/4 = 1/24 x. Of each stolen coat Teddy will get 1/24 (a twenty-fifth) as his remaining share. That is, in order to get one coat to keep for himself, he must steal 24 coats, a bad deal for him!
SOME CLASSIC RIDDLES:
1. Some months have thirty days and some months have thirty-one days. How many months have twenty-eight days
2. At the hardware store I was quoted 12 cents for one, 24 cents for 50, and 36 cents for 144. I wanted six. What was I buying and how much did it cost me
3. If two boys and a girl can beat their father in a tug-of-war, but their mother can win against a boy and two girls, who should win a contest between the father and a girl against the other and a boy
4. If a crab and a half weigh a pound and a half, but the half crab weights half as much again as the whole crab, what do half the whole crab and the whole of the half crab weigh
5. A chessboard has squares that are two inches by two inches by two inches. What is the diameter of the largest circle that can be drawn on the board in such a way that the circle's circumference is entirely on black squares