Answer
1.1 diopters
Work Step by Step
The person’s current near point is 125 cm. With the reading glasses, the screen placed 55 cm from the face (53.2 cm from the lens) should produce a virtual image that is 125 cm from the eye (123.2 cm from the lens).
In other words, $d_o=0.532 m$ and $ d_o=-1.232 m $.
Find the power of the lens from the lens equation.
$$P=\frac{1}{f}=\frac{1}{d_o}+\frac{1}{d_i}$$
$$P=\frac{1}{0.532m}+\frac{1}{-1.232m}=1.1D$$
