Question

of 9. Let A = {1, 2, 3, 4, 5, 6, 7, 8), B = {4, 5, 6, 7, 8, 9, 10). Total number of elements in A delta B is​

Answer 1

Answer:

Solution

Correct option is

C

45

Number of elements in A=10

Number of subsets of A containing exactly two elements

= Number of ways we can select 2 elements from 10 elements

10

C

2

=

2

10×9

=45

∴ Number of subsets of A containing exactly two elements =45

Answer 2

Answer:

Number of elements in A=10

Number of subsets of A containing exactly two elements

= Number of ways we can select 2 elements from 10 elements

10

C

2

=

2

10×9

=45

∴ Number of subsets of A containing exactly two elements =45