Let X = {Ram, Geeta, Akbar} be the set of students of Class XI, who are in school hockey team. Let Y = {Geeta, David, Ashok} be the set of students from Class XI who are in the school football team. Find `X ∪ Y` and interpret the set.

Let U be universal set of all the students of Class XI of a coeducational school and A be the set of all girls in Class XI. Find A′.

Let A be the set of all 50 students of Class X in a school Let f: A to N be function defined by f(x) = roll number of the student x. Show that f in one-one but not onto.

The frequency distribution of the heights (in cm) of 100 students of class X in a school .Find the average height of the students .

Let A be the set of all students of a boys school. Show that the relation R in A given by R = {(a,b):a is sister of b} is the empty relation and R' ={(a,b): the difference between heights of a and b is less than 3 meters } is the universal relation.

There are 40 students in Class X of a school of whom 25 are girls and 15 are boys. The class teacher has to select one student as a class representative. She writes the name of each student on separate cards, the cards being identical. Then she puts cards in a box and stirs them thoroughly. She then draws one card from the box. What is the probability that the name written on the card is the name of (i) a girl? (ii) a boy?

Each x students of class V is given y books. But each x students of class VI is given (y+3) books. Again each (x+11) students of class VII is given (y+10) books. Calculate to find, how many books were given to the students of class V, VI and VII. Also find the total number of books given out in their classes.

Make correct statements by filling in the symbols ⊂ or ⊄ in the blank spaces : { x : x is a student of Class XI of your school}. . .{ x : x student of your school}

Let A be a family of sets and let R be the relation on A defined by X is disjoint from Y . State whether or not R is transitive on A

An educational trip to Gadiyara had been arranged by our school for collection environment related date. 32 studens of class six, 36 students of class seven and 28 students of class eight are going for the trip, few small school buses have been arranged so that each bus must accoumodate equal number of studentsfrom the three classes. Let us find ,total number of buses required and number of students each but will accomodate.

Let ZZ be the set of integers and let R be the relation on ZZ defined as R={(x,y)|x,y in ZZ and x^2+y^2=100} Find R as the set of ordered pairs. Also find its domain and range.