It is given that the rental car charges $0.14 for every mile.
If we have drive for 250 miles, the charge will be
[tex]250\times0.14=35[/tex]Hence the amount is $35 to drive the car for 250 miles.
Then he has at most $290 to spend.The remt for 0ne day is $51
Hence with 290 dollars he can rent a car for
[tex]\frac{290}{51}=5.68\text{ days}[/tex]That is he can travel 5 and a half day with that amount.
If we reduce the cost for miles we get the amount as 290-35=255
With this amount
[tex]\frac{255}{5}=5[/tex]Hence he can travel 5 days 250 miles with the amount he has