10. (5 points) If 2 cows can be exchanged for 42 sheep, 3 sheep can be exchanged for 26 rabbits, 2 rabbits can be exchanged for 3 chickens, then how many chickens can 3 cows be exchanged for?
10. (5 points) If 2 cows can be exchanged for 42 sheep, 3 sheep can be exchanged for 26 rabbits, and 2 rabbits can be exchanged for 3 chickens, then how many chickens can 3 cows be exchanged for?
【Solution】Solution: $42 \div 2=21$ (sheep)
$$
\begin{array}{l}
21 \div 3 \times 26 \\
=7 \times 26 \\
=182 \text { (rabbits) } \\
182 \div 2 \times 3 \\
=91 \times 3 \\
=273 \text { (chickens) } \\
273 \times 3=819 \text { (chickens) }
\end{array}
$$

Answer: 3 cows can be exchanged for 819 chickens.