Analysis: If the rope length is x meters, the rope length after folding is 1/2x meters, and after folding is 1/3x meters. Because it exceeds the well platform by 9 meters after being folded in half, the well depth is reduced by 9 meters, and it exceeds the well platform by 2 meters after being folded in half by 30%, so the well depth is reduced by 2 meters. Because the well depth is equal, so:

Solution: If the rope length is x meters, the well depth is 1/2x-9 meters.

1/2x-9= 1/3x-2

1/2x- 1/3x=9-2

1/6x=7

x=42

Then the well depth is1/2× 42-9 = 21-9 =12m.

Answer: The rope depth is 42m, and the well depth is12m.

This can be solved by binary linear equations, but because it is a primary school problem, it is solved by univariate linear equations.