$(10\%)$ The lens$-$to$-$retina distance of a woman is $2\mathrm{.}03$ cm $,$ and the relaxed power of her eye is $51\mathrm{.}0$ D $.$ a$)$ What is her far point? b$)$ What eyeglass power will allow her to see distant objects clearly, if her glasses are $1\mathrm{.}50$ cm from her eyes?