13 . Tom is practising archery with a target has three concentric zones : a circular bull 's- eye in the centre , an Inner ring , and an outer ring . He has an 0. 12 probability of hitting the bull's- eye , an 0. 37 probability of hitting the inner ring , and an 0. 43 probability of hitting the outer ring . On an given shot , what is the probability that Tom a ) misses the target ? b ) hits the target but does not get a bull 's- eye ? C ) hits the inner ring or the bull 's - eye