Suppose that three girls a, b, and c throw snowballs at a target. suppose also that girl a throws 10 times, and the probability that she will hit the target on any given throw is 0.3; girl b throws 15 times, and the probability that she will hit the target on any given throw is 0.2; and girl c throws 20 times, and the probability that she will hit the target on any given throw is 0.1. determine the probability that the target will be hit at least 12 times