Unpolarized light passes through two crossed polarizers. (a) If a third polarizer is placed between the two crossed polarizers with its axis at an angle of 30^o with respect to the first polarizer, what is the percentage of light transmitted? (b) Instead, if the third polarizer is placed between the two crossed polarizers with its axis at an angle of 45^o with respect to the first polarizer, what is the percentage of light transmitted?