456. Seven children. Four boys and three girls sit in a row in a random order.

What is the probability that the two children at the ends of the row will be girls?

\section*{PUZZLES}
456. Children can sit in 5040 different ways, of which in 720 cases girls will end up at both ends. Therefore, the desired probability is \(\frac{720}{5040}\), or \(\frac{1}{7}\). Of course, this can also be expressed differently, saying that there is 1 chance in 6 that girls will end up at the ends.