power 4dTwo 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.Pick 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. OR