diff --git a/Problems/Problem1.ts b/Problems/Problem1.ts
index fca6ce4..2648980 100644
--- a/Problems/Problem1.ts
+++ b/Problems/Problem1.ts
@@ -1,7 +1,7 @@
 //ProjectEulerTS/Problems/Problem1.ts
 //Matthew Ellison
 // Created: 10-18-20
-//Modified: 10-18-20
+//Modified: 10-26-20
 //What is the sum of all the multiples of 3 or 5 that are less than 1000
 //Unless otherwise listed all non-standard includes are my own creation and available from https://bibucket.org/Mattrixwv/typescriptClasses
 /*
@@ -48,14 +48,8 @@ export class Problem1 extends Problem{
 		//Start the timer
 		this.timer.start();
 
-		for(var num: number = 1;num < 1000;++num){
-			if((num % 3) == 0){
-				this.fullSum += num;
-			}
-			else if((num % 5) == 0){
-				this.fullSum += num;
-			}
-		}
+		//Get the sum of the progressions of 3 and 5 and remove the sum of progressions of the overlap
+		this.fullSum = this.sumOfProgression(3) + this.sumOfProgression(5) - this.sumOfProgression(3 * 5);
 
 		//Stop the timer
 		this.timer.stop();
@@ -68,6 +62,12 @@ export class Problem1 extends Problem{
 		super.reset();
 		this.fullSum = 0;
 	}
+	//Gets the sum of the progression of the multiple
+	private sumOfProgression(multiple: number): number{
+		let numTerms = Math.floor(Problem1.TOP_NUM / multiple);	//Get the sum of the progressions of 3 and 5 and remove the sum of progressions of the overlap
+		//The sum of progression formula is (n / 2)(a + l). n = number of terms, a = multiple, l = last term
+		return ((numTerms / 2) * (multiple + (numTerms * multiple)))
+	}
 	//Gets
 	//Returns the result of solving the problem
 	public getResult(): string{
@@ -86,5 +86,6 @@ export class Problem1 extends Problem{
 }
 
 /* Results:
-
+The sum of all numbers < 1000 is 233168
+It took an average of 1.921 microseconds to run this problem through 100 iterations
 */