##### Probability that a hash table using chaining for collision resolution has a chain of atleast 3 out of 4 keys.

why option c is wrong becoz making of atleast 3 chain size it will probability of 1/8 ?

why option c is wrong becoz making of atleast 3 chain size it will probability of 1/8 ?

Since , it is given 4 keys are there , then we can say that chain of size 3 and 4 can be obtained.

^{8}C_{1}*^{4}C_{3}*^{7}C_{1}/8^{4}//^{8}C_{1}for select ing 1st slot for a chain of length 3 ,^{4}C_{3 }for selecting 3 out of 4 keys to form chain ,^{7}C_{1 }for selecting 2 nd slot for holding 1 key^{8}C_{1}/8^{4}^{8}C_{1}*^{4}C_{3}*^{7}C_{1}/8^{4 }+^{8}C_{1}/8^{4}29/ 8

^{3}