187. Elementary arithmetic. Here is one question similar to those that were so popular in Venice (and not only there) in the mid-16th century. Their appearance was largely due to Niccolò Fontana, better known as Tartaglia (the stammerer).

If a quarter of twenty were four, then what would a third of ten be?
187. The answer is the number \(2 \frac{2}{3}\). To find it, a proportion needs to be set up: \(5: 4=3 \frac{1}{3}: 2 \frac{2}{3}\).