Your Job
	Find the sum of all multiples of n below m
	
	Keep in Mind
	n and m are natural numbers (positive integers)
	m is excluded from the multiples
	Examples
				

	sumMul(2, 9)   ==> 2 + 4 + 6 + 8 = 20
	sumMul(3, 13)  ==> 3 + 6 + 9 + 12 = 30
	sumMul(4, 123) ==> 4 + 8 + 12 + ... = 1860
	sumMul(4, -7)  ==> "INVALID"
				

Solution by -

	function sumMul(n,m){
		let arr =[]
		for(let i = 1;(i * n) < m; i++){
			arr.push(n * i)
		}
		return n == 0 || m == 0 || m < n ? 'INVALID' : arr.reduce((x,y) => x+y,0)
		}
				

Try it yourself - CodeWars

	Your Job
	Find the sum of all multiples of n below m
	
	Keep in Mind
	n and m are natural numbers (positive integers)
	m is excluded from the multiples
	Examples
				

	sumMul(2, 9)   ==> 2 + 4 + 6 + 8 = 20
	sumMul(3, 13)  ==> 3 + 6 + 9 + 12 = 30
	sumMul(4, 123) ==> 4 + 8 + 12 + ... = 1860
	sumMul(4, -7)  ==> "INVALID"
				

Solution by -

	function sumMul(n,m){
		let arr =[]
		for(let i = 1;(i * n) < m; i++){
			arr.push(n * i)
		}
		return n == 0 || m == 0 || m < n ? 'INVALID' : arr.reduce((x,y) => x+y,0)
		}
				

Try it yourself - CodeWars