Answer:
Qn.1
{4,5,6,7,8,9,12,15,16}is ans of 1
{8,9}is ans of 2
{4,5,6,7,8,9,18,20}is ans of 3
{}Is the ans of 4
{8,9,12,15,16,18,20}is ans of 5
{}is ans of 6
{4,5,6,7,8,9,12,15,16,18,20} is ans of 7
{8,9,12,15,16} is ans of 8
Qn.2
{0,12}is ans of 9
{0,2,10,12}is ans of 10
{0,4,6,8,12}is ans of 11
{2,4,6,8,10}Is ans of 12
{}is ans of 13
{0,12}is ans 14
{0,12} is ans 15
{0,2,10,12} is ans of 16
{0,12} is ans of 17
{0,12} is ans of 18
{2,10} is ans of 19
{4,6,8} is ans of 20
I haven't made the symbol of union and intersection because i don't how to make.
it may help you at your work