What Should Be the Focal Length of Kat's Corrective Contact Lenses?

[hardwork]

Homework Statement

Without her contact lenses, Kat cannot clearly see an object more than 70.0cm away. What should be the focal length of her corrective contact lenses?

Homework Equations

1/f = 1/p + 1/q

The Attempt at a Solution

1/f = 1/infinity + 1/-70.0cm = -0.0143cm
f = -70.0 cm

Would anyone be able to please check this answer? Thank you!

 

[rl.bhat]

Your answer is correct.