Question 7 Given a string str of length N, consisting of '(' and ')' only, the task is to check whether it is balanced or not. PRACTICE NOW Question 8 Write a program to check if a sentence is a palindrome or not. You can ignore white spaces and other characters to consider sentences as a palindrome. Question 9 Given a string str, the task is to find the longest substring which is a palindrome. PRACTICE NOW Question 10 Given a string, the task is to count all palindrome sub string in a given string. Length of palindrome sub string is greater than or equal to 2. Question 11 Given a set of strings, find the longest common prefix.