This measurement tells you how packed in a substance is. The higher the density, the more the object weighs for a certain volumetric unit (such as a cubic meter). Eg: a cubic meter of feathers is likely to weigh less than a cubic meter of solid gold because the feathers have a lot more air in them as opposed to the gold which is more compact.
density = mass/volume is the formula you often use
Well i did 120/15 and got 8 so he runs a mile every 8 minutes about. so you do 8 x 6 because he has to run 6 miles and bam 48 it takes him 48 minutes to run 6 miles. he runs about (.125) miles an hour ( i was assuming you meant 15 miles in 120 minutes)
