diff --git a/src/multiplication.c b/src/multiplication.c
index d0fcf59..e222e4d 100644
--- a/src/multiplication.c
+++ b/src/multiplication.c
@@ -1,7 +1,7 @@
 #include "multiplication.h"
 #include <stdio.h>
 #include <string.h>
-
+#include <math.h>
 
 
 double multi( double ein1, double ein2) {
@@ -31,7 +31,7 @@ float multiply_by_percentage(float num, float percentage) {
 }
 
 int multiply_by_random(int num) {
-    int random_factor = rand() % 10 + 1; 
+    int random_factor = random_factor % 10 + 1; 
     return num * random_factor;
 }
 
@@ -108,5 +108,9 @@ int multiply_using_increment(int num1, int num2) {
     return result;
 }
 
+int multiply_by_prime_and_its_square(int num, int prime) {
+    return num * (prime + square (prime));
+}
+
     
 
diff --git a/src/multiplication.h b/src/multiplication.h
index 4955c4d..bd20e4a 100644
--- a/src/multiplication.h
+++ b/src/multiplication.h
@@ -17,6 +17,7 @@ int multiply_using_logical_operations(int num1, int num2);
 int multiply_using_modulo(int num1, int num2, int modulo);
 int multiply_by_prime(int num, int prime);
 int multiply_using_increment(int num1, int num2);
+int multiply_by_prime_and_its_square(int num, int prime);
 
 
 #endif // MULTIPLICATION_H