The correct answer is 6*10 arranging or 10*6 arranging. You need to find the minimum of 2(x+y), where x and y are positive integer numbers under the condition xy = 60. To simplify your arguments, consider all possible factoring of 60 into the product of two integer x and y : 60 = 1*60 = 2*30 = 3*20 = 4*15 = 5*12 = 6*10 and calculate 2*(x+y) for each pair.