Answer Happy

3) A man wears glasses with a power of 3 diopters and must hold a newspaper 30cm from his eyes to see clearly. How far from his eyes should you put the newspaper to see clearly without glasses. Show all calculations.
3) Un hombre usa espejuelos de potencia 3 dioptrias debe mantener un periódico a 30 cm de sus ojos para ver claramente. A que distancia de sus ojos debe poner el periódico para verlo claramente sin espejuelos. Muestre todos los cálculos.