Answer:
See explaination.
Explanation:
question is the root element which have two children one is M-C and other is Coding.
Again M-C have two sub children Points and parts
Note: The tree will be as shown in the attachment. kindly refer to attachment.
Here if we see the child of quiz(questions) at 0 position is number of type M-C and another child at location 1 is number of type Coding.
Now quiz.child(0) is number of type M-C which has two child and child at 0 is Points and child at 1 is Parts
quiz.child(0).child(1) is Points and now further points doesn't have any children hence going further to quiz.child(0).child(1).child(0) is nothing hence it will not return anything.
Next quiz.child(1) is number of type coding and value is 5.
Size of the tree is (2^depth)-1
and here depth of tree is 3 hence size is (2^3)-1 i.e. 7