For the following questions answer them individually
If a convex lens forms a real inverted same size image at 30 cm, then the object is placed _____ in front of the lens.
Pure ghee costing Rs.100 per kilogram and vegetable oil costing Rs.50 per kilogram are mixed in some ratio and sold at Rs.96 per kilogram so as to gain 20%. In what ratio is ghee and oil mixed?
