69. In the store, there are candies at 2 p. and 3 p. per 1 kg, each type for the same amount of money. At what price should the mixture of these candies be sold to keep the total cost of the candies the same?
69. Let the cost of each type of candy be $a$ rubles. Then at a price of 2 rubles per 1 kg, there was $a: 2=\frac{a}{2}$ (kg), and at 3 rubles $-\frac{a}{3}$ kg. In total, there was $\frac{a}{2}+\frac{a}{3}=\frac{5 a}{6}$ (kg), so the average price per 1 kg of the mixture will be $2 a: \frac{5 a}{6}=\frac{12}{5}=2.4$, i.e., 2 rubles 40 k. (not 2 rubles 50 k.).