a)

Number of nodes with 2 children = x

Number of nodes with 1 children = y

Number of nodes with 0 children = z

Total Degree = 2*Edges

3x + 2y+ z -1(because of root node) = 2(x+y+z-1)

x - z = -1 Therefore False

b)

Deletion takes O(log n) so O(n) also correct. It's True

Number of nodes with 2 children = x

Number of nodes with 1 children = y

Number of nodes with 0 children = z

Total Degree = 2*Edges

3x + 2y+ z -1(because of root node) = 2(x+y+z-1)

x - z = -1 Therefore False

b)

Deletion takes O(log n) so O(n) also correct. It's True