Problem:

Question 1- Create a static method that when given a 7 digit word (string) converts it to telephone number and writes the resulting number to a file named "{netid_1.txt}". The signiture of the method must be.

public static void wordToNumber7(String number )

Question 2- Create a static method that when given a 10 digit word (string) converts it to a telephone number and writes the resulting number to a file named {netid}_2.txt. The signiure of the method must be.
public static void wordToNumber10(String number)

Question 3- Write a decoder to decode text encoded with the following proceedure, you need to reverse the process and write the results to a file anmed {netid}_3.txt

Please can anyone help me to answer these question in detail.