At what position a candle of length 3 cm be placed in front of a convex lens so that it's image of length 6 cm be obtained on a screen placed at distance 30 cm behind the lens

Answer 1

Height of object=3cm
Height of image=-6cm (formed below principle axis )
V=30 cm
U=?
By using lens formula we get f=10cm
hi/ho=v/u
-6/3=30/u
U=-15 cm

Answer 2

Wrong answer

Answer 3

Very good good good good 👍