Focal length of glasses

[phy112]

Homework Statement

Veronique is nearsighted; she cannot see clearly anything more than 6.50 m away without her contacts. One day she doesn't wear her contacts; rather, she wears an old pair of glasses prescribed when she could see clearly up to 8.00 m away. Assume the glasses are 2.0 cm from her eyes.

a. What is the focal length of Veronique's glasses?
b. What is the greatest distance an object can be placed so that she can see it clearly with these glasses?

Homework Equations

1/p-1/q=1/f

The Attempt at a Solution

I literally have no idea where to start. any hints appreciated

 

[phy112]

so i got -7.98 for the focal length. but i don't know how to do b