Question

On a number line, find the midpoint of a segment with the following endpoints:
A = -10 and B = 20

Answer 1

the distance is 30, (20-(-10)
1/2 of 30 is 15, so from an end point go 15 units towards the other midpoint.
I choose 20, so the midpoint would be at +5 on the number line.

Answer 2

change on the 2nd line "midpoint" to read "endpoint"