C PROGRAMMING PROGRAM • BASICS & INPUT/OUTPUT

Calculate Simple Interest

Learn how to calculate simple interest using a clear C program.

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PROBLEM UNDERSTANDING

Input and expected output

Sample input

10000 6.5 2

Sample output

Simple interest = 1300.00
Total amount = 11300.00

COMPLETE C PROGRAM

Complete C implementation

#include <stdio.h>

int main(void)
{
    double principal, rate, time, interest;

    printf("Enter principal, annual rate and time: ");
    scanf("%lf %lf %lf", &principal, &rate, &time);
    interest = principal * rate * time / 100.0;
    printf("Simple interest = %.2f\n", interest);
    printf("Total amount = %.2f\n", principal + interest);
    return 0;
}

CURRENT STEP

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SELECTED LINE

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EXPECTED OUTPUT FOR THE SAMPLE

Simple interest = 1300.00
Total amount = 11300.00

0%Step 0 of 0

PROGRAM EXPLANATION

Algorithm and explanation

Read the required input values.
Use P×R×T/100 and add the interest to the principal.
Display the computed result.

Use P×R×T/100 and add the interest to the principal.

EFFICIENCY

Time and space complexity

Time complexity

O(1)

Auxiliary space

O(1)

DEBUGGING CHECKLIST

Common mistakes

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Use the correct format specifier for every variable.

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Initialize variables before using their values.

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Check braces, semicolons and input order carefully.

Try it yourself

Practice: Run the program with the sample input, predict its output, and then test one boundary case of your own.