GATE CS 2015 Set 1 — Question 42
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Engineering Mathematics → Probability & Statistics → Partial Orders & Lattices
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Question
Suppose is a lattice represented by the following Hasse diagram:

For any , not necessarily distinct, and are join and meet of , respectively. Let be the set of all ordered triplets of the elements of . Let be the probability that an element chosen equiprobably satisfies . Then

For any , not necessarily distinct, and are join and meet of , respectively. Let be the set of all ordered triplets of the elements of . Let be the probability that an element chosen equiprobably satisfies . Then
Correct answer
(D) (1)/(5) < pᵣ < 1
Solution
Reading the Hasse diagram. is the bottom and is the top. The three middle elements (left), (centre) and (right) each cover and are each covered by ; no two of them are comparable. This is the diamond lattice :
- for distinct middle elements : and .
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