Note 1: Negative numbers will always be less than positive numbers.
Note 2: A positive number closer to 0 is less than one that is farther away from 0.
Note 3: Negative numbers are the opposite of positive numbers. A negative number closer to 0 is greater than one that's farther away from 0.
A) -8 < 1 < 7
-8 is inevitably first in set A since it's the only negative number. (positive)1 is closer to 0 than (positive)7 is. In result, 1 is less than 7. The question asks for numbers LEAST from greatest.
Therefore A: -8,1,7
B) -13 < -2 < 17 < 20
Take a look at note 2 and 3. -13 is the smallest value because it's a negative number that's the farthest away from 0. -2 is a lesser number, although second to -13 given that -2 is closer to 0 than -13 is.
17 is less than 20. 17 is closer to 0 than 20 is.
Therefore B: -13, -2, 17, 20
C) -6 < -1 < 0 < 4 < 6 < 10
-6 is the smallest value because it's a negative number that is farthest away from 0. -1 is a negative number as well thus relatively (to almost all present values aside from -6) a lesser value. 0 is greater than any negative number. 4 is closer to 0 compared to 6 and 6 is closer to 0 compared to 10.
Therefore C: -6, -1, 0, 4, 6, 10