Answer:
The height of the image will be "1.16 mm".
Explanation:
The given values are:
Object distance, u = 25 cm
Focal distance, f = 1.8 cm
On applying the lens formula, we get
⇒ 
On putting estimate values, we get
⇒ 
⇒ 
⇒ 
As a result, the image would be established mostly on right side and would be true even though v is positive.
By magnification,
and
⇒ 
⇒ 
⇒ 
Hope this shows! It has all the equations for all of the problems u asked in the comments
If she only has 21 buttons and all 21 of them are large, then all of her buttons are large. so 100% of the buttons would be large.