Answer 1

Given:
Object distance, u =   -10 cm 
(Since object is always placed on the left side of lens)
Focal length, f = +10 cm
According to lens formula: 

`1/v-1/u=1/f` 

`1/v=1/f+1/u` 

`1/v=1/10=(-1/10)=0`  

`v=1/0= oo`  

Therefore, the position of image will be at infinity.