This is direct variation, because as the number of days increase, the number of miles also increase.

 

Writing the ratio of miles to the number of days, it would be 508 : 7  : :  x :30, where x is number of miles driven in 30 days

 

 

This means 508/7 = x/30

 

Hence x = 508(30)/7

               = 2177.14 miles

 

 

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