In a mixture of concrete, there are four lb of cement mix for each pound of gravel. If the mixture contains a total of 190 lb of these two ingredients, how many pounds of gravell are there?
Split 190 lb into 5 parts, so 1 part = 190/5 = 38.
Since the 190lb must be 4 parts cement and 1 part gravel there must be 38 lb gravel.
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