Henry Ernest Dudeney/Modern Puzzles/15 - Sawing Logs/Solution

by : $15$

 * Sawing Logs

Solution
$50$ shillings.

Proof
The workman charges for the number of cuts per log.

A cord is a unit of volume.

$4$ cords of $6$-foot logs is the same number of logs as $2$ cords of $3$-foot logs.

The key point is that:
 * it takes $2$ cuts to cut a $3$-foot log into $1$-foot pieces

but:
 * it takes $5$ cuts to cut a $6$-foot log into $1$-foot pieces.

So the workman should charge:
 * $30 \times \dfrac 2 3 \times \dfrac 5 2 = 50 \shillings$