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).

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.

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

I made the same mistake speed reading the question. {1,2,3,4,5,6,7,8} is the union of both sets BUT the question is how many elements are in the union.

Actually, this problem need to first customize the input like below(Check the box of "Test against custom input"):

{1,2,3,4,5,6} {2,3,4,5,6,7,8}

where i should write the answer?

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

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

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.

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