2. a) In your own words, explain what is meant by the Abstract Data Type (ADT) o tree. marks) a. Making use of the above phrases, state the time complexity of the algorithms described by EACH of the following growth functions: i. T (n) = 20 + 23n3 + 3n : log2n+ 55n2 ii. T (n) = (32n+ 1)(log2(n)- 2) + 3n 12 marks) b. Making use of an appropriate Big-O expression, state the time complexity of the algorithms described by EACH of the following growth functions: i. T (n) = 251000 ii. T (n) = {ni=1(4i) + 3500 + 17n log2(n) iii. T (n) = 6n3+ / 3 log2(n) + 31000n2 marks) b. The standard Java package java.util includes class TreeMap. Explain why it is not recommended to use java.util.TreeMap to model a tree in your Java application. o marks)