Power 4D

power 4dPick your 4D Powerball numbers 3 ways to increase your chances to win: add more 4D numbers, Powerballs, or both to form more combinations. Just add RM2 for every possible Powerball combination you get from your Combo Play. ORTwo lenses have power of (i) + 2 d (ii) -4D. What is the nature and focal length of each lens? b. An object is kept at a distance of 100 cm from lens of power -4D. Calculate the image distance.