A concave mirror has a focal length of 25 cm. At which of the following distace should a person hold his fce from this concave mirror so that it may act as a shaving mirror ?
(a) 45 cm
(b) 20 cm
25 cm
(c ) 25 cm
(d) 30 cm
Give reason for your choice.
A. N/A
B. N/A
C. N/A
D. N/A