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.

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).

the answer is 8 you have to input the number 8 on the first line of the window else it shows an error

Gangsters You'll need to Enter the answer in Editor As well as in custom input

Answer is: 8

Hello there, you just need to enter how many elements are present in the union (AUB). You don't need to list out all. That's the catch :) Hope this helps!

I don't know how to write answer to the query. I know how to do mathematically but how to write here.

You i started to doupt everything around me, I know the result is 8, but when i submitted it showing "Wrong answer" ...

after a while, i was submitting the number with an extra space that made the answer wrong ..

so ((8) != (8 )) .. apparently ...

you know it is reallly ironic that your website teach programming, and you don't know about the trim() method ..

No sample test-cases for this question. Please test your code against custom input.