A promising new method of treating various types of lymphomas uses beta particles from the decay of 90Y (each with an energy of about 1.44 x 10 -13 J) to aggressively destroy cancerous cells. If a 2.10 kg mass of body tissue exposed to the radiation absorbed 3.60x105 beta particles, and the RBE factor is 0.80, how many REMS did the patient absorb