1.

(a) Let T be a tree with vertices of degree 1 and 3 only. If T has 10 vertices of degree 3, how many vertices does it have of degree 1?

(b) Let G be a connected graph with n vertices and n edges. How many cycles does G have?

(c) How many leaves in a complete 3-ary tree with 10 internal nodes?

could someone explain to me how to do those plz. thanks!