Henry Ernest Dudeney/Modern Puzzles/18 - A Curious Paradox/Solution

by : $18$

 * A Curious Paradox

Solution
First guess: the small amount difference spans the threshold between tax brackets, which he would have had to pay to the government.

Proof
explains it in some detail, the gist of which is as follows:

A payment of $\pounds 2$ invoked a cost to the recipient of $1 \oldpence$, leaving him with $\pounds 1 \ 19 \shillings 11 \oldpence$.

Recall:


 * $1$ pound sterling ($\pounds 1$) is $20$ shilling ($20 \shillings$)
 * $1$ shilling is $12$ (old) pence ($12 \oldpence$)


 * The man came to the shop $1 \oldpence$ short, with $\pounds 1 \ 19 \shillings 11 \oldpence$.

At that selling price the tax does not apply.

So paying a penny less is no loss to the seller.

So the initial guess was correct: it was a tax thing.