Word problems › Money and shopping › Best buy within a budget
Maximum pencils with cashback
Middle school · ●●●○○ 50 pts
Vasya's mother gave him exactly enough money to buy 30 pencils. All pencils cost the same. A store promotion works as follows: for a receipt for a set of 20 pencils, the factory returns 25% of the set's cost, and for a receipt for a set of 5 pencils, it returns 10% of the set's cost. The refunds can be spent on further purchases. What is the maximum number of pencils Vasya can buy?