C Program To Find Simple Interest

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Write a C program to find the simple interest.

Simple Interest is the interest paid on the principal amount for which the interest earned regularly is not added to the principal amount.

Examples

Input: Principal = 1000, Rate = 5, Time = 2
Output: Simple Interest = 100

Input: Principal = 2000, Rate = 3.5, Time = 4
Output: Simple Interest = 280

How to Find Simple Interest in C?

To find the simple interest in the C programming language, we can directly implement the simple interest formula with the required values such as rate, time, and principal amount as input since there is no built-in C function to calculate it directly.

Simple Interest Formula

Simple Interest = Principal * Rate * Time​ / 100

Simple Interest Program in C

// C program to find the simple interest
#include <stdio.h>

int main() {
  
    // Input values
    float P = 1, R = 1, T = 1;

    // Calculate simple interest
    float SI = (P * T * R) / 100;

    // Print Simple Interest
    printf("Simple Interest = %f\n", SI);

    return 0;
}

Simple Interest = 0.010000

Time Complexity: O(1)
Auxiliary Space: O(1)

Simple Interest Calculator Using Function

We can also define a function name smpInt() that takes rate, time and principle as arguments at returns the simple interest. It is more convenient when we need to find the simple interest frequently.

// C Program to Calculate Simple Interest using Functions
#include <stdio.h>

// Function to calculate simple interest
float smpInt(float p, float r, float t) {
    return (p * r * t) / 100;
}

int main() {
        // Input values
    float P = 10000, R = 12, T = 1, SI;

   
    // Call function to calculate simple interest
    SI = smpInt(P, R, T);

    // Display the result
    printf("Simple Interest: %.2f\n", SI);

    return 0;
}

Simple Interest: 1200.00

Time Complexity: O(1)
Auxiliary Space: O(1)