Verb/Subject Agreement Make/Makes

I'm not sure about the proper subject verb agreement in the following sentences.

A boy and a girl make/makes a couple.

5 and 5 make/makes 10.

75 and 25 make/makes a hundred.

Can you help?

ETA: I understand that compound subjects usually take plural verbs, unless they form a collective idea- in which case it takes a singular verbs.

Can the subjects in these cases be considered a collective unit?

I think the right answer would be the following.

1. A boy and a girl make a couple, because they make.

2. 5 and 5 makes 10, because I understand you're trying to convey sum, and that would be 5 plus 5, or it makes.

3. 75 and 25 makes 10, because I understand you're trying to convey sum, and that would be 75 plus 25, or it makes.