Henry Ernest Dudeney/Puzzles and Curious Problems/32 - Apple Transactions/Solution

by : $32$

 * Apple Transactions

Solution

 * $8 \shillings$

Proof
Let $p$ be the price per apple in pence.

Let $n$ be the number of apples that were bought for $10 \shillings$, that is, $120 \oldpence$.

Then we have:

Only the positive root is appropriate here.

Hence:
 * $p = \dfrac {96} {100}$

That is, the price for $100$ apples is $96 \oldpence$, which works out as $\dfrac {96} {12} = 8 \shillings$