

(a)
The maximum possible magnification is obtained when image is formed at near point (d= 25 cm)
Image distance (v) = -d = -25 cm
Focal length (f) = 10 cm
Object distance (u) =?
Using lens formula
1/f = 1/v -1/u
1/u = 1/v -1/f
1/u = 1/-25 - 1/10 = -2-5/50 = -7/50
u = 50/7 = -7.14 cm
Hence lens should be placed 7.14 cm away from them
(b)
Magnification = v/u 25/50/7 = 25 x7/50 = 3.5
(c)
Magnifying power = d/u = 25/50/7 = 25 x 7/50 = 3.5
