13.200. Two skins with a total cost of 22500 rubles were sold at an auction with a profit of $40 \%$. What is the cost of each skin if a profit of $25 \%$ was made on the first one, and $50 \%$ on the second one?
Solution.

Let $x$ rubles be the cost of the first pelt, and 22500 - $x$ rubles be the cost of the second. The first pelt was sold for $1.25 x$ rubles, and the second for $1.5(22500-x)$ rubles. According to the condition, $1.25 x + 1.5(22500-x) = 1.4 \cdot 22500$, from which $x = 9000$ rubles.

Answer: 9000 and 13500 rubles.