A dartboard has 10 equally sized slices numbered from 1 to 10. Some are grey and some are white. The slices numbered 1,2 ,3 ,5 ,6 ,8 , and 9 are grey. The slices numbered 4,7, and 10 are white. A dart is tossed and lands on a slice at random. Let X be the event that the dart lands on a grey slice, and let P (X) be the probability of X . Let not X be the event that the dart lands on a slice that is not grey, and let P ( not X) be the probability of not X .