Given : u=−15‌cm,f=−10‌cm,ho=4‌cm
Using the mirror formula
‌

1

v

+‌

1

u

‌=‌

1

f

‌

1

v

−‌

1

15

‌=‌

−1

10

‌

1

v

‌=‌

−1

10

+‌

1

15

‌

1

v

‌=‌

−15+10

150

=‌

−5

150

v‌=−30‌cm
Thus, to obtain a sharp image of the object, the screen should be placed in front of the mirror at a distance of 30‌cm.
Now,
m=‌

−v

u

=‌

‌ height of image ‌

‌ height of object ‌

m=−(‌

−30

−15

)⇒m=−2
−2=‌

hi

4

⇒hi=−8‌cm
∴ Height of the image is 8‌cm. (inverted)