Question

Write a program to calculate and print the sum of each of the following series :

i. S=2-4+6-8+…………-20

ii. S=(1+2)/(1x2)+(1+2+3)/(1x2x3)+(1+2+3+4)/(1x2x3x4)+……. +(1+2+3+4…..n)/( 1x2x3x4x…..n)​

Answer 1

Answer:

//Program using switch case

import java.util.*;

public class Series

{

public static void main(String args[ ])

{

Scanner in=new Scanner(System.in);

int ch;

System.out.println("Enter 1 for sum of Series 1");

System.out.println("Enter 2 for sum of Series 2");

System.out.println("Enter your choice");

ch=in.nextInt();

switch(ch)

{

case 1:

int a,s=0;

for(a=2;a<=20;a=a+2);

{

if(a%2==0)

s=s-a;

else

s=s+a;

}

System.out.println("The sum of the given series="+s);

break;

case 2:

int n,b;

double sum=0.0

System.out.println"Enter n");

n=in.nextInt();

for(b=1;b<=n;b++)

{

sum=sum+(double)(b+(b+1))/(b*(b+1));

}

System.out.println("The sum of the given series="+sum);

break;

default:

System.out.println("Invalid choice");

}

}

}