Reg No.:

Max. Marks: 100

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Pages: 3

Name:
APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY

Third semester B.Tech examinations (S) September 2020

Course Code: 5201
Course Name: DISCRETE COMPUTATIONAL STRUCTURES

PARTA
Answer all questions, each carries 3 marks.

Show that A x (BNC) = (AxB)N (AxC)
Prove that if a relation R on set A is transitive & irreflexive, then it is
asymmetric.
If 9 books are to be kept in 4 shelves, there must be atleast one shelf which
contains atleast 3 books. Justify
In how many ways can 6 boys and 4 girls sir in a row? In how many ways can
they sit in a row if just the girls are to sit together?

PART ‏تا‎

Answer any two full questions, each carries 9 marks.

Consider f, g and h are functions on set of integers.
f(n)=n+2, g(n)=n’, h(n)=3n. Determine fogoh, gofoh, hofog, fog.
If S=N x N and the binary operation * is defined by (a,b)*(c,d)=(ac,bd) for all
a,b,c,d in N, show that (S,*) is a semigroup. Is it monoid?
Which of the following relations on {0,1,2,3} are equivalence relation? Justify
the answer.
R1={(0,0),(1,1),(2,2),(3,3)}
R2={(0,0),(0,2),(2,0),(2,2),(2,3),(3,2),(3,3) }
R3={(0,0),(1,1),C1,2),(2, 1),(2,2),(3,3) }
R4={(0,0),(1,1),(2,2),(,3,3),(2,3),(3,2) }
Find the number of integers between | and 250 both inclusive that are not
divisible by any of the integers 2,3,5
Solve the recurrence relation a, - 2a,-) = 3" : ‏5عرج‎
‎Determine whether POSET represented by Hasse diagram given below have

greatest element, least element, minimal element, maximal element.

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Duration: 3 Hours

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