9000148905
Level:
A
The king has eight daughters. A dragon asks two daughters, otherwise he will
destroy the whole country. In how many ways can we choose a pair of king's
daughters for the dragon?
\(\frac{8!}
{2!\; 6!}=28\)
\(8\cdot 7=56\)
\(8^{2}=64\)
\(8 + 7=15\)