A camera with a lens of focal length 10 cm takes a picture of a 160 cm girl standing 24.0 m away. What is the approximate height of the image?

1/di+1/do=1/f

1/di+1/24=1/10

24/di=2.4-1
di=1.4/24 meters=1.4/24 m

then M=di/do=hi/ho
solve for hi, about ho*di/do=160*1.40/24