Universal Relations

Q.

A relation which has all the elements of set A is called universal relation on set A

1. True

2. False

Q.

How many elements will be there in the universal relation defined on the set A = {1, 4, 9}

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Q. If a relation $R$ is defined on $A=\{1,2,3,4\}$, then which of the following is/are universal relation?

1. $R=\left\{\right(a,b):a+b<10:a,b\in A\}$
2. $R=\left\{\right(a,b):\text{value of}a-b\text{is an integer}:a,b\in A\}$
3. $R=\left\{\right(a,b):\text{value of}\frac{a}{b}\text{is an integer}:a,b\in A\}$
4. $R=\left\{\right(a,b):ab\text{is a real number}:a,b\in A\}$