Answer:
Image distance = 60 cm
Explanation:
Object distance from a convex lens = 20 cm
Focal length of convex lens = 15 cm
Use the following relation between the object distance, focal length and image distance.
[tex]\frac{1}{object\,\,distance}+\frac{1}{image\,\,distance} =\frac{1}{focal\,\,length}[/tex]
[tex]\frac{1}{20}+\frac{1}{image\,\,distance}=\frac{1}{15}\\\\ \frac{1}{image\,\,distance}= \frac{1}{15}-\frac{1}{20}\\\\ \frac{1}{image\,\,distance}= \frac{4-3}{60} \\\\ \frac{1}{image\,\,distance}=\frac{1}{60}[/tex]
Therefore,
Image distance = 60 cm
