15 kg of cherries were collected and packed into two boxes. The first box contained two-fifths of the total amount of cherries collected. How many kilograms of cherries are in the second box?

Решение:

1. Найдем, сколько килограммов вишни в первом ящике:\[ 15 \text{ кг} \times \frac{2}{5} = \frac{15 \times 2}{5} = \frac{30}{5} = 6 \text{ кг} \]
2. Найдем, сколько килограммов вишни во втором ящике:\[ 15 \text{ кг} - 6 \text{ кг} = 9 \text{ кг} \]

Ответ: 9 кг