Respuesta :
3 1/8 + 1 2/5 = 4 21/40 because the least common denominator is 40. So 5x8=40 and 2x8=16. Then 8x5=40 and 1x5=5. Next you add the numerators and get 21/40. And last but not least you add the whole numbers to get a final answer of 4 21/40