How can I recommend this to folks who want to learn SQL if the mathmatical operators aren't defined before questions are asked about them. It's pretty hard to google set union if you've never seen it before... I'd love some more explanation for the math.

where i should write the answer?

i just answered on the editorial box. but it didn't work.

SORRY CAN ANYONE HELP ME WHAT I NEED TO DO , I MEAN I KNOW WHAT IT IS UNION ,BUT I DONT UNDERSTAND HOW I NEED TO CODE , OR HOW TO ANSWER IT DIRECTLY PLEASE HELP.CAN I DO IT WITH PYTHON OR I NEED TO DO IN SQL

print 8 in both text editor and custom input

write exactly the correct integer. If the answer is 5 just type, 5 Click submit code don't hit run code. that's it

The union of two sets is the set of elements which are in either set (8).

The intersection of two sets is the set of elements which are in both sets (5).

i am getting my answer in dev c++ fr this problem but hee its showing wrong answer.can anyone help me?

Always remember to read the question thoroughly . I managed to rack up at least five failures on this exercise because I read it as "Lists the elements of the union of X and Y..." rather than "How many elements in the union of X and Y?"

My stupidity aside, it's always a good idea to make sure you thoroughly understand your goal when working on a programming or maths related problem.

Everytime I submit the answer it says wrong answer. Can you help me....

why the answer is not 5 as letter 2,3,4,5,6 numbwers are common in both sets