A 50-year-old man uses + 2.5-D lenses to read a newspaper 25 cm away. Ten years later,

Question:

A 50-year-old man uses + 2.5-D lenses to read a newspaper 25 cm away. Ten years later, he must hold the paper 38 cm away to see clearly with the same lenses. What power lenses does he need now in order to hold the paper 25 cm away? (Distances are measured from the lens.)