C# Question & Answers on Maths Class for Freshers

1. Which of these classes contains only floating point functions?

a) Math
b) Process
c) System
d) Object

Answer: a

Explanation: Math class contains all the floating point functions that are used for geometry, trigonometry, as well as several general purpose methods. Example : sin(), cos(), exp(), sqrt() etc.

2. What will be the output of the given code snippet?

1.  class Program

2.  {

3.      static void Main(string[] args)

4.      {

5.          double x = 2.0;  

6.          double y = 3.0;

7.          double z = Math.Pow( x, y );

8.          Console.WriteLine(z);

9.          Console.ReadLine();

10.      }

11.  }

a) 2.0
b) 4.0
c) 8
d) 8.0

Answer: c

Output :8

3. What will be the output of the given code snippet?

1.  class Program

2.  {

3.      static void Main(string[] args)

4.      {

5.          double x = 4.772;

6.          double y = 4.76;

7.          double z = Math.Max(x, y);

8.          Console.WriteLine(z);

9.          Console.ReadLine();

10.      }

11.  }

a) true
b) false
c) 4.772
d) 4.76

Answer: c

Output :4.772

4. What is the value of double constant ‘E’ defined in Math class?

a) approximately 3
b) approximately 3.14
c) approximately 2.72
d) approximately 0

Answer: c

5. What will be the output of the given code snippet?

1.  public class A

2.  {

3.      public int x;

4.      public int y;

5.      public void display() 

6.      {

7.          Console.WriteLine(x + " " + y);

8.      }

9.  }

10.  class Program

11.  {

12.      static void Main(string[] args)

13.      {

14.          A obj1 = new A();

15.          A obj2 = new A();

16.          obj1.x = 1;

17.          obj1.y = 2;

18.          obj2 = obj1;

19.          obj1.display();

20.          obj2.display();

21.      }

22.  }

a) 1 2 0 0
b) 1 2 1 2
c) 0 0 0 0
d) Run time exception

Answer: b

Output : 1 2 1 2

6. What will be the output of the given code snippet?

1. class Program

2. {

3.     static void Main(string[] args)

4.     {

5.         int[] nums = { 1 };

6.         var posNums = from n in nums

7.                       select Math.Pow(4 ,3);

8.         Console.Write("The values in nums: ");

9.         foreach (int i in posNums) 

10.         Console.Write(i + " ");

11.         Console.WriteLine();

12.         Console.ReadLine();

13.     }

14. }

a) Run time error
b) 64
c) Compile time error
d) 81

Answer: b

Output :64

7. What will be the output of the given code snippet?

1. class Program

2. {

3.     static void Main(string[] args)

4.     {

5.         float x = 3.14F;

6.         int y = (int)Math.Abs(x);

7.         Console.WriteLine(y);

8.         Console.ReadLine();

9.     }

10. }

a) Compile time error
b) 3.14
c) 3
d) 4

Answer: c

Output :3

8. What will be the output of the given code snippet?

1. class Program

2. {

3.     static void Main(string[] args)

4.     {

5.         int x = 5;

6.         int y = (int)Math.Pow(x,2);

7.         int z = (int)Math.Pow(y, 2);

8.         Console.WriteLine(z);

9.         Console.ReadLine();

10.     }

11. }

a) 25
b) 625
c) Compile time error
d) Run time error

Answer: b

Explanation: y = 25 , z = 25*25 = 625
Output :625

9. What will be the output of the given code snippet?

1.  class Program

2.  {

3.      static void Main(string[] args)

4.      {

5.          int[] nums = {3 ,1 ,2 ,5 ,4};

6.          var ltAvg = from n in nums

7.                      let x = nums.Average()

8.                      where n < x

9.                      select n;

10.          Console.WriteLine("The average is " + nums.Average());

11.          Console.ReadLine();

12.      }

13.  }

a) Run time error
b) 3
c) 5
d) Compile time error

Answer: b

Explanation: Built in method of maths class Avg() id used
Output :3

10. What will be the output of the given code snippet?

1. class Program

2. {

3.     static void Main(string[] args)

4.     {

5.         int y = (int)Math.Max(4,2);

6.         int z = (int)Math.Pow(y, 2);

7.         Console.WriteLine(z);

8.         Console.ReadLine();

9.     }

10. }

a) 4
b) Compile time error
c) 16
d) 89

Answer: c

Explanation: Built in method of maths class, Max() is used to select maximum value among 4 and 2 and then y is squared using Pow() of math class and the value is stored in z.
Output :16