Statisitcal test??? Help please

So for my psych class we had to conduct an experiment and me and my friend decided to do a disney experiment to see the difference between boys and girls, it was a score out of 20, to see which gender got more correct. We have to do a statistical test and I dont know which one??? There are two groups (boys and girls) and they both experienced the same conditon so its independent design, i think? Its a test of difference. I dont know whether it is interval or ordinal data.

I've tried the Mann whitney test but its coming up with a negative U value and thats not supposed to happen. I think it might be unrelated T but im not sure? I need to do it for tommorow.
Helpppp please!

So it's quasi-experimental, because what you're varying is the gender of the groups. What's the DV, performance on a Disney quiz?

What about a between subjects t-test?

I know there may be issues with normality of data, but the t-test is very robust.

Isn't a between subjects design for when your groups are in different conditions (I.e. boys get a car quiz and girls get a Disney quiz). I think the Mann Whitney U is correct and I think that having a negative U is not a problem? Does that not just mean that the second group had lower ranks than the first - I'm not sure about that, which is why I deleted my first post.

There are different conditions, one group of participants is male, the other female. That's what the OP is manipulating, independent variable= gender, dependent variable= performance. Although like I said, it's quasi-experimental.

See this example from laerd statistics- https://statistics.laerd.com/spss-tutorials/independent-t-test-using-spss-statistics.php
They've used a t-test to test for difference between genders in graduate salaries. IV= male, female. DV= salary.

Like I said, the only possible issue is with normality of data, but generally for a large group of participants it's fine.

I can't really speak for a U, but I'm pretty sure for a t-test you can ignore the sign (negative/ minus), because you'd use a graph to illustrate the direction of the difference anyway.So I imagine it's the same with the Mann Whitney?