A rope over the top of a fence has the same length on each side.  The rope weighs one-third 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 as the age of the monkey.  The weight of the monkey in ounces is as much as the age of the monkey's mother.  The combined ages of the monkey and the monkey's mother are thirty years.  Half the weight of the monkey, plus the weight of the banana, is a fourth as much as the weight of the weight and 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's 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 a 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 a fourth as old as it is now.

How long is the banana?