You are given 1 ml of a 50 mM stock solution of NADPH. You are told to dilute it so that its absorbance in the spec 20 equals 0.80. The molar extinction coefficient for NADPH is 6220 liters per mole cm and the path length is 5 cm. The volume of the tube is 10 mls. How many micromoles of stock NADPH do you transfer?