Identify the operator that gets the highest precedence while evaluating the given expression:

a + b % c * d - e

1. +
2. %
3. -
4. *

Evaluate the given expression when the value of a=2 and b=3

b*=a++ - ++b + ++a;
System.out.println("a= "+a); 
System.out.println("b= "+b);

Write a Java program to obtain principal amount, rate of interest and time from user and compute simple interest.