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 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.

Find the mean of the marks obtained by 30 students of class IX of a schoo.

Let cup be the set of all boys and girls in a school, G be the set of all girls in the school, B be the set of all boys in the school and S be the set of all students in the school who take swimming. Some but not all, students in the school take swimming. Draw a Venn diagram showing one of the possible inter relationship among sets cup , G, B and S.

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

List all the subsets of the set { –1, 0, 1 } .

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.

The donations given to an orphanage home by the students of different classes of a secondary school are given below. Find the mean, median and mode of the data.

Let U be the set of all triangles in a plane. If A is the set of all triangles with at least one angle different from 60°, what is A′?

Write down all the subsets of the following sets phi