The focal length will be = 2.67 cm
The distance between the convex lens or a concave mirror and the focal point of a lens or mirror is called the focal length. It is the point where parallel rays of light meet or converge.
given
u (object distance) = 260 cm
v (image distance) = 2.70 cm
f (focal length) = ?
using lens formula
1/f = 1/u + 1/v
= 1/260 + 1/2.70
= 2.67 cm
The focal length will be = 2.67 cm
To learn more about focal length here
https://brainly.com/question/14104969
#SPJ4