Reference no: EM132736890
MT131 Discrete Mathematics - Arab Open University
Q-1: Without using truth tables, determine whether the proposition (p∧(p?q))?q is a tautology.
In the questions below suppose the variable x represents students and y represents courses, and: U(y): y is an upper-level course, M(y): y is a math course, F(x): x is a freshman, B(x): x is a full-time student. Write the statement using these predicates and any needed quantifiers.
All students are freshmen.
Every freshman is a full-time student.
No math course is upper-level.
Q¬-2:
Suppose that a,b,c∈Z. show that if a^2 |b and b^3 |c then a^6 |c.
Suppose that a∈Z. show that if a is odd then a^2+3a+5 is also odd.
Let a,b∈Z and n∈N. Show that if a≡b (mod n) and a≡c (mod n), then c≡b (mod n).
Q¬-3:
Suppose that A,B,C and D are sets. Prove that (A×B)∪(C×D)⊆(A∪C)×(B∪D).
Let B={2^n |n∈Z}. Show that the function f:Z→B defined as f(n)=2^n is bijective. Then find f^(-1).
Q¬-4:
This problem involves 8-digit binary strings such as 10011011 or 00001010.
How many such strings are there?
How many such strings end in 0?
How many such strings have 1's for their second and fourth digits?
How many such strings have 1's for their second or fourth digits?
Find how many 9-digit numbers can be made from the digits 1, 2, 3, 4, 5, 6, 7, 8, 9 if repetition is not allowed and all the odd digits occur first (on the left) followed by all the even digits.
How many permutations of the letters A, B, C, D, E, F, G are there in which the three letters ABC appear consecutively, in alphabetical order?
Q¬-5:
Two cards are dealt off a well-shuffled deck. You win $1 if the two cards are of different suits. Find the probability of your winning?
A coin is tossed 5 times. What is the probability that the first toss is a head or exactly 2 out of the five tosses are heads?
In a shuffled 52-card deck, what is the probability that neither the top nor the bottom card is a heart?
A bag contains 20 red marbles, 20 green marbles and 20 blue marbles. You reach in and grab 15 marbles. What is the probability that they are all the same colour?
Attachment:- Discrete Mathematics.rar