Discrete Structures BS 3 Semester/Term UOG — University of Gujrat 2020

UNIVERSITY OF GUJRAT

Mid Term Examination- Fall 2020

Department of Computer Science

Course name: Discrete Structures

Course Code: CS-261

Time allowed: 2.5 hrs

Program: BCS-III

Name:

Roll no:

Marks: 25

Instructions:

• Understanding question is the part of the exam. No queries will be entertained.

• Attempt your questions as per question paper's sequence and write answers precisely.

• Avoid cheating while attempting your paper from any resource; otherwise you will be

given penalty by negative marking.

• Write complete details on your answer sheet regarding university name, campus name,

Batch-code, Roll-no, Course-name, Course-Code, Instructor, Exam Date/Time. Write

total no of pages on the Title page duly signed by you.

• Mark page number at the bottom right corner of each page of your answer sheet.

Answer the following questions?

1. Convert the following statements into propositional logic: [2.5]

i. You cannot download a journal paper from IEEE unless you are a IEEE member.

ii. You get promotion only if you have references and you have references only if

you get promoted.

iii. When an email is not sent from an unknown system it is not scanned for viruses.

iv. The email was sent from an unknown system but it is not scanned for viruses.

v. Wireless access is granted whenever the user has paid the subscription fee and

enters a valid password.

2. Convert the following conditional statements into the converse, contrapositive, and

inverse statements. [2.5]

i. If it snows today, I will go for entertainment today.

ii. I come to class whenever there is going to be a viva.

3. For each of these sentences, explain how exclusive or (XOR) works on the following

propositional statements. [2.5]

i. Developer post requires experience with C++ or php.

ii. Lunch includes soup and salad.

iii. To enter in university premises, you need NIC or university card.

iv. Dinner for two includes two items from solid food or three items from fast food.

v. To take discrete mathematics course, you should have read mathematics or

computer Science.

CS-261-DISCRETE STRUCTURES 1