268. Someone has workers and money. If he gives each worker 5 (coins), he will have 30 left, but if 7, then he will be short of 30. The question is, how many workers does he have?

Problems by N. Chuquet from the treatise “Triparty...”.
268. If each person is given two more coins, the difference turns out to be 60 coins, therefore, there were 30 workers.

Shyukе Nicolas (died in 1500), French mathematician, author of the treatise "Le Triparty en la science des nombres" (1484), in which zero and negative exponents are used for the first time.