Question

an object 5 cm in size is placed at a distance of 20cm from a concave mirror of focal length 15cm.find v and h'

Answer 1

Firstly use sign convention then apply mirror formula you get v then apply magnification formula and you get the value of m then again apply magnification formula by taking h and h' then you get h'
v=8.57cm
h'=11.90cm

Answer 2

$\textbf{Answer is in Attachment !}$