Now, before anyone tries to solve this puzzle, I should warn you that I do not know the answer. I’ve had this thing for years, typed out on an old, yellowed piece of paper. I don’t even remember where I got it. I’ve never gotten around to solving it, and, for all I know, there may not be a solution. Anyway… enjoy.
Monkey Business
A rope over the top of a fence has the same length on each side. It weighs one third of a pound per foot. On one end hangs a monkey holding a banana, and on the other end is a weight equal to the weight of the monkey. The banana weighs two ounces per inch. The rope is as long (in feet) as the age of the monkey (in years), and the weight of the monkey (in ounces) is the same as the age of the monkey’s mother. The combined age of the monkey and its mother is thirty years. One half the weight of the monkey plus the weight of the banana is one fourth as much as the weight of the weight plus the weight of the rope. The monkey’s mother is half as old as the monkey will be when it is three times as old as its mother was when she was half as old as the monkey will be when it is as old as its mother will be when she is four times as old as the monkey was when it was twice as old as its mother was when she was one third as old as the monkey was when it was as old as its mother was when she was three times as old as the monkey was when it was one fourth as old as it is now.
I have a bunch of bananas sitting in a basket on the fridge. I measured one of them. I’m not sure I understand your reference. I am not from the east coast.
More to the point: How old is the banana?
Is the monkey likely to get ptomaine poisoning? Or worse, Jungle Rot?
Monkeys usually haven’t had food safety training.
I’m sorry to see this thread descending into silliness so soon. Obviously, if the banana is getting over-ripe, the monkey would make banana bread (my fave). And for you fact-bound anal types, before you ask how I know this, be informed that I was born in the year of the monkey, and have inside information.
The fridge is about 35 years old, and is that repulsive avacado green they used to like back then. Any other, newer, self-defrosting type fridges I have had die after a year or two due to how hot it gets in here during the summer, but this tiny old warhorse just keeps on chugging along. It owes me nothing.
Assumption: Friction is neglected. Thus the total weight on each side of the rope has to be the same, otherwise it would slide to one side or the other.
“On one end hangs a monkey holding a banana, and on the other end is a weight equal to the weight of the monkey.”
With the stated assumption, in order for the above to be true, monkey+banana = monkey. That can’t be if the monkey is holding the banana in its hand/tail/etc.
Proposal - The monkey has eaten the banana and is holding it in its stomach. It has become part of the monkey’s mass/weight. Therefore the banana has no length because it is no longer a seperate entity with its own dimensions.
My 12 year old son said to tell all of you old foggies to go back to school. (Hey, I’m just the messenger.) He sat here staring at the problem then said it has to be between 5 1/2 inches and 6 inches. As he got up to leave, I asked him how he knew that. He said he did the math by estimating something (I don’t know what he’s talking about when he gets like this). His parting shot as he left the room was, “What else could it be – just think about it, Dad.”
