What percentage of Africans live in sub-Saharan Africa? * a less than 10%
b about 50%
c about 65%
d about 85%

How long does it take hair to grow 8 inches?

People keep spending additional units of a particular resource on a want until their marginal benefit is  decreasing withgreater thanless thannot affected by  their marginal cost.

Match the following items. 1 1 (4,4) 2. (-4,-2) 3. (3.-6) 4. (-4, 6) 5. (1,5)