diff --git a/Math/Sum of 7's Multiple.cpp b/Math/Sum of 7's Multiple.cpp
new file mode 100644
index 0000000..02299a5
--- /dev/null
+++ b/Math/Sum of 7's Multiple.cpp	
@@ -0,0 +1,7 @@
+long Solution::solve(int A, int B) {
+    if(A%7) A+=(7-A%7);
+    B-=B%7;
+    int n=(B-A)/7+1;
+    long long result=(long)n * long(A+B)/2;
+    return result;
+}