That would be any number greater or equal to 15, and smaller than 25.
165
Rounded to the nearest whole number it is 10
10
The number 3400 is already rounded to the nearest 10.
10
9.8 rounded to nearest whole number is 10.
20
10
10
10001/999900
Rounded to the nearest whole number it is 10
Rounded to the nearest whole number it is 10