Q1. WAP to convert Dollar into Rupees and vice versa, Assume 1 dollar = 74.5 rupees. 1

#include<stdio.h>
#include<conio.h>

void main()
{
    int ch;
    float r, d, dollar=74.5;
    printf("Enter 1 - Rupees to Dollar\n");
    printf("Enter 2 - Dollar to Rupees\n");
    scanf("%d",&ch);
    switch(ch)
    {
        case 1:  //Rupees to Dollar
            printf("Enter Rupees:");
            scanf("%f",&r);
            d=r/dollar;
            printf("Dollar = %.2f",d);
        break;
        case 2:  //Dollar to Rupees
            printf("Enter Dollar:");
            scanf("%f",&d);
            r=d*dollar;
            printf("Rupees = %.2f",r);
        break;
        default:
            printf("Invalid Input! Try Again!");
        break;
    }
    getch();
}

Q2. WAP to convert Dollar into Rupees and vice versa, repeat the program till user exits. 1

#include<stdio.h>
#include<conio.h>

void main()
{
    int ch;
    float r, d, dollar=74.5;
    while(1){
        printf("Enter 1 - Rupees to Dollar\n");
        printf("Enter 2 - Dollar to Rupees\n");
        printf("Enter 0 - Exit\n");
        scanf("%d",&ch);
        switch(ch)
        {
            case 1:  //Rupees to Dollar
                printf("Enter Rupees:");
                scanf("%f",&r);
                d=r/dollar;
                printf("Dollar = %.2f",d);
            break;
            case 2:  //Dollar to Rupees
                printf("Enter Dollar:");
                scanf("%f",&d);
                r=d*dollar;
                printf("Rupees = %.2f",r);
            break;
            default:
                printf("Invalid Input! Try Again!");
            break;
        }
	}
    getch();
}