Two point sources S1 andS2 are 24cm apart where should a convex lens of focal length 9 cm be placed in between         them so that the images of both sources are formed at the same place

when both will produce image at the same place one will be real and other will be virtual if distance of one object from the lens is x other will be 24-x for one object 1x+1v=19----1 for other 124-x-1v=19-----2 solving we get x=6 or 18