Exercises and Sample Questions (Set I)

1.) Write an if decision statement that will check if a number is even.

2.) In a quadratic equation ax2 + bx + c = 0, the quantity b2 – 4ac 
     is called the discriminant and is used to determine the type 
     of solutions of the equation.  Write a valid C statement (only 
     the mathematical statement is necessary) that computes the 
     discriminant and assigns it to the variable D.

3.) Write a decision statement(s) that will display the message “x 
      is larger than y and positive” if x is both greater than y and positive.

4.) What is the output?

      int i = 4;
      if ( i == 1 )
          cout << "Code red" << endl;
      if ( i == 2 )
          cout << "Code yello" << endl;
      if ( i == 3 )
          cout << "Code blue" << endl;
      else
          cout << "Code undefined" << endl;

5.)  What is the output?

      int i = 1;
      if ( i == 1 )
          cout << "Code red" << endl;
      if ( i == 2 )
          cout << "Code yello" << endl;
      if ( i == 3 )
          cout << "Code blue" << endl;
      else
          cout << "Code undefined" << endl;

6.)  What is the output?

      int x = 4;
      while ( x >= 1) {
          x = x - 2;
          cout << "x = " <<  x  << endl;  }

7.)  Given the following if statements:

      if ( Score == 'A')
         if ( Difficulty >= 7.0)
            TotalScore = 4.0 * Difficulty;

        a.)  What type of variables (data type) should Score, Difficulty, and TotalScore be, respectively?

        b.)  Write an equivalent compound if.

8.)  Given the following switch statement in the code segment:

      int answer;
      cin >> answer;
      switch (answer)  {
      case 5:    cout << "The answer is 5";
                    break;
      case 10:  cout << "The answer is 10";
                    break;
      case 15:  cout << "The answer is 15";
                    break;
      default:   cout << "Invalid input";
                    break;
      }

      Convert the switch statement and all its cases to an equivalent if construct.