A coin is 33.3 cm from a concave spherical mirror. (Assume the coin is on the optical axis.) The image of the coin is produced 23.3 cm closer to the mirror than the original object. Calculate the focal length of the mirror. O 15.4 cm O 10.0 cm O 7.69 cm O 13.7 cm What is the magnification m of the coin in the previous problem? O - 0.300 O - 0.700 O + 0.300 O + 0.700