A population of 80 rats is tested for 4 genetic mutations after exposure to some chemicals: mutation A, mutation B, mutation C, and mutation D. 43 rats tested positive for mutation A. 37 rats tested positive for mutation B. 39 rats tested positive for mutation C. 35 rats tested positive for mutation D. One rat tested positive for all four mutations. 5 rats tested positive for mutations A, B, and C. 4 rats tested positive for mutations A, B, and D. 6 rats tested positive for mutations A, C, and D. 3 rats tested positive for mutations B, C, and D. 64 rats tested positive for mutations A or B. 63 rats tested positive for mutations A or C. 59 rats tested positive for mutations A or D. 58 rats tested positive for mutations B or C. 59 rats tested positive for mutations B or D. 60 tested positive for mutations C or D. 8 rats did not show any evidence of genetic mutation. What is the probability that if 4 rats with mutations are selected at random, at most 2 rats will have exactly 1 mutation? PS; answer must be 0.9987. Thank you