Henry Ernest Dudeney/Puzzles and Curious Problems/169 - Shooting Blackbirds/Solution

Puzzles and Curious Problems by Henry Ernest Dudeney: $169$

Twice four and twenty blackbirds

Were sitting in the rain;

I shot and killed a seventh part,

How many did remain?

$4$.

The reader is initially tempted into thinking of:

Twice four and twenty

as meaning:

$2 \times 24$

and then is left scratching one's head at the absurdity of finding an integer solution to $x = \dfrac {48} 7$.

In fact:

Twice four and twenty

is interpreted as:

$\paren {2 \times 4} + 20$

which gives $28$.

Hence $\dfrac {28} 4 = 4$ were shot, leaving $24$ remaining.

But no! This is a trick puzzle.

The $24$ which were not shot flew away, leaving $4$ (dead) blackbirds remaining.

I hope Dudeney was pleased with himself.

$\blacksquare$