Originally posted by Darlek2354
I don't know if this has already been done, but I was asked this riddle in college, and just cannot work out the answer. Any ideas, clues or solutions would be appreciated
There was a rope hanging over a pulley with a weight on one end and a monkey on the other. The rope weighs 400g/m; the age of the monkey and the age of it's mother were together equa and the weight of the weight and the weight of the monkey.
What was the length of the rope?
Well, it all seems to depend on mother's age... let's call the variables:
Ww=weight that's hanging on the rope
Wr=weight of the rope
Lr=length of the rope
Am1 is the age of the monkey when it was 3 times younger than the mm. Then, 3*Am1=Amm1 (mm's age at that time).
Thus 9*Am1=monkey's age when it will be 3 times as old as the mother at thet time. Then Amm2 (mm's age, when it is half as old as m will be)should be 9*Am1/2=4.5*Am1
In the first line of the previous paragraph I expressed the Amm1 in terms of Am1. The difference in their ages thus wil be (3-1)Am1=2Am1. From here continuing the last paragraph, the monkey's age at that time will be 2.5*Am1
So, 5*Am1=mm's age now, and 3*Am1=m's age now. Thus 5*Am1+3*Am1=8 yrs=>Am1=1year (age of the monkey when the mother was three times as old)
So, the m (and thus the Ww) = 5 kg
Set the two parts of the pulley equal:
Now, factor label: 2.5kg=2500g*1m/400g=6.25m
I guess, that's right, but I'm not sure.
P. S. Sorry for my disorganization