Henry Ernest Dudeney/Puzzles and Curious Problems/234 - Pile Driving/Solution

by : $234$

 * Pile Driving

Solution

 * $26$ feet $3$ inches.

Proof
Let $L$ feet be the length of the pile.

You may be tempted to do this:

No no no!

The part of the pile buried in the mud is also under water.

So:

and it is seen that the proportion of the pile which is buried in mud is no more than a distraction.