Question

question 15 solve this numerical​

Answer 1

distance b/w lens is 25 cm converging lens means convex lens for convex focal length is positive and distance of object from 1st lens is 50 cm this put with negative sign 1/f= 1/v-1/u where u=-50 then you found v=+25/2 means b/w two lens this is image distance for 1st but object for 2nd and then 1/f =1/v=1/u where u is -25/2 for 2nd lens then you found +50 image distance from 2nd lens then intial object distance to final image distance are 50+25+50= 125 cm