Calculate the total number of electrons detected by the anode of a PM tube used with a NaI(Tl) scintillator given the following conditions: A 1.5 MeV electron loses all its energy in the scintillator, the light collection efficiency to the photocathode is 50%, the average quantum efficiency of the photocathode is 20%, and 80% of the photoelectrons are collected at the first anode. Assume that the PM tube has 10 stages with a multiplication factor = 2.5 per stage. The absolute light yield for NaI(Tl) is 38,000 photons/MeV.