The high was 20. the low was -15. what is halfway between high and low?

I think its 19. should be right

There are two bc a studen that equals to 2

The first one, i believe, would be correct. all the others have one thing in common, and that's that they have repeating numbers. in the second one, x and y have repeating 6's and 3's, and in the third, x and y have repeating 6's as well. in the last one, there are repeating 3's. the first one has no repeating numbers.