6 answers
8
A binary tree $T$ has $n$ leaf nodes. The number of nodes of degree $2$ in $T$ is$\log_2 n$$n-1$$n$$2^n$
7 answers
10
Two girls have picked $10$ roses, $15$ sunflowers and $15$ daffodils. What is the number of ways they can divide the flowers among themselves?$1638$$2100$$2640$None of th...