Can two threads call a synchronized method and normal method at the same time?

Problem

You are given a class with synchronized method A, and a normal method C. If you have two threads in one instance of a program, can they call A at the same time? Can they call A and C at the same time?

Solution:
Java provides two ways to achieve synchronization: synchronized method and synchronized statement.

• Synchronized method: Methods of a class which need to be synchronized are declared with “synchronized” keyword. If one thread is executing a synchronized method, all other threads which want to execute any of the synchronized methods on the same objects get blocked.
  
  Syntax: method1 and method2 need to be synchronized
  

  public class SynchronizedMethod {
      // Variables declaration
      public synchronized T Method1() {
          // Statements
      }
      public synchronized T method2() {
          // Statements
      }
      // Other methods
  }  
  

  
  T is return type. 
• Synchronized statement: It provides the synchronization for a group of statements rather than a method as a whole It needs to provide the object on which these synchronized statements will be applied, unlike in a synchronized method
  
  Syntax: synchronized statements on "this" object
  

  synchronized(this) {
      // statement 1
      // ...
      // statement N
  }
  

i) If you have two threads in one instance of a program, can they call A at the same time?
Not possible; read the above paragraph.
ii) Can they call A and C at the same time?
Yes. Only methods of the same object which are declared with the keyword synchronized can't be interleaved

References

• http://tianrunhe.wordpress.com/2012/05/04/can-two-threads-call-a-synchronized-method-and-normal-method-at-the-same-time/