Bitwise Operator - C Programming

Question

Problem Statement: Class teacher to IX-C wants to store whether a particular student has passed in exams. The class has a strength of $32$ students. Their roll numbers lie in the range: $[1, 32]$. The teacher used bits of an integer to store the information. This integer is called storage integer. Set bit or bit with value $1$ of this storage integer denotes that the student has passed and vice versa for unset bit.

Question: The class teacher has to conduct an advanced exam. Only students who have passed this exam will be eligible for the advanced exam. Now, the seating arrangement has been made with VII-C, which also has the same strength of $32$ students. The seating arrangement is to be made in such a way that roll number one of IX-C and VII-C have to sit together, similarly for roll number two and so on. If roIl number one of IX-C is ineligible, then VII-C student will sit alone.

If the storage integer of both the classes is given to you, then which of the following operators will you use to find the count of students that are sitting in pairs.

Options: Pick one correct answer from below

a. Apply Bitwise XOR (^) operator and count number of unset bits

b. Apply Bitwise NOT (~) operator and count number of set bits

c. Apply Bitwise OR (|) operator and count number of set bits

d. Apply Bitwise AND (&) operator and count number of set bits

Comments

yupp that's why question maker have to specify little bit extraa. for $Vii $ $C$ students.

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Storage integer for VII C is given - why more information is needed?

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yes sir now i got it i was thinking that they should mentioned seprately just like they did for 9th C students.

Answer 1

Option d) AND operator
if both students from the corresponding classes are ineligeble , 0AND0 =0 , not counted
any one student ineligeble , 0AND1 or 1AND0 =0 not counted
only 1AND1=1 is counted , so we AND both the integers and count the no of set bits

Answer 2

Same as the number of set bits in the original 32 bit number, that defines the passing/failing status of the IX-C students.

Because only their passing/failing status matters in determining if sitting will be in pairs or single.