It is: (20+30)/2 = 25
30
30
20
The number 30, itself, is a decimal number. So it is the nearest.There is no other "nearest" number. If there were, the number halfway between that number and 30 would be nearer to 30. And then the number halfway between that number and 30 would be nearer still. And so on.
25
It is 25
It is 27.5, the number halfway between the two middle numbers.
Halfway between 30 and 80 is (30 + 80) ÷ 2 = 55.
50
32
It is: 48
It is: 30