EASY
Earn 100

Define the family of sets with one example.

Important Questions on Sets

HARD
Let a>0, a1. Then, the set S of all positive real numbers b satisfying 1+a21+b2=4ab is
MEDIUM
Set A has m elements and set B has n elements. If the total number of subsets of A is 112 more than the total number of subsets of B, then the value of m·n is___.
MEDIUM
Let S=xR:cosx+cos2x<2, then
EASY
If A and B are disjoint sets, then BA', where A' is complement of A, is equal to
HARD
Let Z be the set of integers. If A=xZ: 2x+2x2-5x+6=1 and B={xZ  :-3<2x-1<9}, then the number of subsets of the set A×B, is :
MEDIUM
An investigator interviewed 100 students to determine the performance of three drinks milk, coffee and tea. The investigator reported that 10 students take all three drinks milk, coffee and tea; 20 students take milk and coffee, 30 students take coffee and tea, 25 students take milk and tea, 12 students take milk only, 5 students take coffee only and 8 students take tea only. Then the number of students who did not take any of the three drinks is
EASY
If the total number of m-element subsets of the set A=a1,a2,,an is k times the number of m element subsets containing a4, then n is
MEDIUM
If A=a1, a2, .a10: a1{1, 2, 3}, a1+ai+1 is even, 1i9, then the number of elements in the set A is
MEDIUM
Let A and B be two sets containing 2 elements and 4 elements respectively. The number of subsets of A×B having 3 or more elements is :
HARD
Let A, B and C  be sets such that ϕABC. Then which of the following statements is not true?
EASY
If a set A has 4 elements, then the total number of proper subsets of set A, is
HARD
Let A and B be two sets containing four and two elements respectively. Then the number of subsets of the set A×B, each having at least three elements is
EASY
Which of the following is an empty set?
HARD

Let A be the set of vectors a=a1,a2,a3 satisfying i=13ai2i2=i=13ai22i. Then,

EASY
The number of proper subsets of a set having n+1 elentents is
HARD
A positive integer k is said to be good if there exists a partition of 1,2,3,.,20 into disjoint proper subsets such that the sum of the numbers in each subset of the partition is k. How many good numbers are there?
EASY
The total number of subsets of the set {1, 2, ,10} which do not contain the element 6 is
EASY
Two finite sets have m and n elements. The number of subsets of the first set is 112 more than that of the second. The values of m and n are respectively
EASY
Let S=1, 2, 3, .,100, then number of non-empty subsets A of S such that the product of elements in A is even is :
MEDIUM
If X=4n-3n-1:nN  and Y=9n-1:nN, then XY=