What is the image distance of an object 1.30 m in front of a converging lens of focal length 20.0 cm?

Question

Quizplus · Accepted Answer

We can use the thin lens equation: 
1/f = 1/do + 1/di 
where f is the focal length, do is the object distance (1.30 m in this case), and di is the image distance (what we're solving for). 
Plugging in the values: 
1/0.20 = 1/1.30 + 1/di 
Solving for di: 
di = 0.236 m = +23.6 cm 
Therefore, the answer is (C).

What Is the Image Distance of an Object 1