zJosh cannot see objects clearly beyond  25 cm (his far point). If he has no astigmatism and contact lenses are prescribed for him, what power and type of lenses are required

Naiya wears glasses to correct her nearsightedness. The lenses have a power of Pi -2.50 D, and they are just powerful enough to allow Naiya to clearly focus on distant objects (i.e., objects located at infinity). Unfortunately, her glasses have gone missing, so today she is forced to wear her backup pair. The backup pair has a weaker prescription, but otherwise the two pairs of glasses are identical. Using the backup pair, she is only able to clearly focus on objects if they are closer than = 4.0 m from the lenses. What is the power P2 of the lenses in her backup pair? (Hint: your far point doesn't change when you take off your glasses.) Make sure that your representation indicates all the relevant details of the problem, such as: im- age distance, object distance, far point, lens-eye distance, lens shape, etc.

Is this question set up wrong?  I think the statement "The magnification of a book held 7.50 cm from a 10.0 cm-focal length lens is 3.00." is impossible using the lens equation 1/do + 1/di = 1/f and the equation for magnification m = -di / do.

6. A nearsighted man uses his ideally prescribed eyeglasses that have a refractive power of -3.00 diopters. He would like a prescription for contact lenses. What is the correct contact lens distance of 2.0 cm from his eyes? diopters ssf60 ss prescription if he normally wears his eyeglasses a f60 ssf60 pre 0 ssf60 sta