Calculate population density

population=300
Area (km)2 = 40
population density=?

How would i answer this in a exam. orange - sea temperature is over 27 red arrows - tropical storm routes

What's erosion? a. the breakdown of rock into smaller pieces b. the removal of weathered products from rock c. a change in rock resulting from exposure to water d. a chemical change in rock that weakens it

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.