A concave mirror produces 3 times enlarged image of an object placed at 10cm in front of it. Calculate the focal length of the mirror

Magnification =3 We know that Magnification =-image distance/object distance 3=-image distance/-10 Hence, image distance =30 cm Now, Image distance(v)=30cm Object distance(u)=-10cm By mirror formula 1/v+1/u=1/f 1/f=1/30+1/-10 1/f=1/30-1/10 1/f=1/30-3/30 1/f=-2/30=-1/15 Therefore f=-15cm