Question

IfA={1,2,3,4} B={2,4,6} C={1,3,5,7} andU={1,2,3,4,5,6,7} then B−C

Answer 1

`B-C=\{2,4,6\}`

Explanation:

We are given the following sets:

`A=\{1,2,3,4\}\\ B=\{2,4,6\}\\ C=\{1,3,5,7\}\\ and\\U=\{1,2,3,4,5,6,7\}`

To find:
`B-C = ?`

Solution:

Here, we are given 4 sets,

The universal set, U and its 3 proper subsets A,B and C.

Proper subsets are the subsets which have at least one element which is extra in the super set.

Now, let us have a look at the definition of 'minus' in terms of sets.

Minus is defined as the set of elements which contains the elements of first set which are not present in the other set.

OR

The common elements are not written.

For example:

P = {10,20,30}

Q = {10,40,70}

P - Q = {20,30}

Common element(s) of P
`\cap` Q = {10} is/are not written in P-Q.

Here, there are no common elements in B and C.

`\therefore B-C = B`

OR

`B-C=\{2,4,6\}` is the correct answer.