Let a be the number of positive multiples of 6 that are less than 30. let b be the number of positive integers that are less than $30$, and a multiple of $3$ and a multiple of $2$. compute $(a - b)^3$.

0 or -3375

Explanation:

The question is somewhat ambiguous because we can't be sure whether B will be positive integers which are multiples of both 3 and 2 or 3 and 2 separately.

For the former:

There a 4 multiples of 6 less than 30: 6, 12, 18, 24.

Positive integers (whole numbers) less than 30: 1-29 ; multiples of 3: 3, 6, 9, 12, 15, 18, 21, 24, 27 and of those, only 6, 12, 18 and 24 are multiples of both 2 and 3.            

Therefore we have (4-4)^3 = 0

For the latter:

multiples of 3: 3, 6, 9, 12, 15, 18, 21, 24, 27 ; Multiples of 2:  2 4 6 8 10 12 14 16 18 20 22 24 26 28 (remove common multiples)

Therefore (4-19)^3 = -3375

C) Grady is more concerned with economic investment, while Douglass is more worried about voter disenfranchisement.

Explanation:

Both Frederick Douglass and Henry W. Grady were concerned with the way Reconstruction was to take place in the South. Douglass believed that one of the most important aspects that needed to be discussed was the disenfranchisement that many people suffered. This particularly concerned African Americans. On the other hand, Grady believed that economic interests should take precedence. He envisioned a "New South" that was industrialized and moved away from the economics of plantations.