Questions

#include<stdio.h>

int main(){

  int a[10][10],i,j,sum=0,m,n;

  printf("\nEnter the row and column of matrix: ");
  scanf("%d %d",&m,&n);

  printf("\nEnter the elements of matrix: ");
  for(i=0;i<m;i++)
      for(j=0;j<n;j++)
           scanf("%d",&a[i][j]);
  printf("\nThe matrix is\n");

  for(i=0;i<m;i++){
      printf("\n");
      for(j=0;j<m;j++){
      printf("%d\t",a[i][j]);
      }
 }
 for(i=0;i<m;i++){
     for(j=0;j<n;j++){
          if(i==j)
              sum=sum+a[i][j];
     }
 }
 printf("\n\nSum of the diagonal elements of a matrix is: %d",sum);

 return 0;
}

Sample output:

Enter the row and column of matrix: 3 3
Enter the elements of matrix:
2
3
5
6
7
9
2
6
7
The matrix is
2       3       5
6       7       9
2       6       7
Sum of the diagonal elements of a matrix is: 16

Acid which is present in vinegar is approximately 5 % of acetic acid. This can be confirmed by testing the vinegar with magnesium which gives out hydrogen as a gas.

Caverns are openings in the ground. Some famous caverns in the United States are Mammoth Cave, Carlsbad Caverns, Wind Cave, and Luray Caverns.

When rainwater trickles down through the soil, it carries carbon dioxide from the air with it. This turns acidic as it moves through the soil, joining with carbon from decaying plants. This acidic rainwater then eats away at, or erodes, the rock under the ground, forming a cave or cavern. For this process to occur, the rock must be the right type; limestone, dolomite, and gypsum are common.

Ram Nath Kovind, the present President of India is from BJP, Bharatiya Janata Party.

The president of the Republic India is the head of state of India. He is also the commander-in-chief of Indian Armed Forces. He is indirectly elected by the people through members of both houses of the parliament of India, legislative assemblies of all the states of India, the legislative assembly of the Union

Upari refers to a category of tenancy tenure held under the Maratha Regime.The Government used to assign land to various cultivators for cultivation and getting maximum revenue. The land allotted to original settlers of villages came to be known as Mirasi land whereas the land assigned to the migrant settlers was known as the Upari land.

'Rare earth'(They are all metals)

There are many isotopes of uranium and all of them have same atomic number i.e, sum of nmber of neutrons and protons.