Third of 12 by 7 over 5 is 11

Puzzle

One third of twelve if you divide

By just one fifth of seven,

The true result (it has been tried)

Exactly is eleven.

Solution

One third of $\mathtt {TWELVE}$ is $\mathtt {LV}$ which is $55$ in Roman numerals.

One fifth of $\mathtt {SEVEN}$ is $\mathtt {V}$ which is $5$ in Roman numerals.

Then we have that:

$\dfrac {55} 5 = 11$

Sources

• 1821: John Jackson: Rational Amusement for Winter Evenings
• 1992: David Wells: Curious and Interesting Puzzles ... (previous) ... (next): Rational Amusements for Winter Evenings: $149$