It all depends on how much fuel is at that time and how big the fuel tank is.
1500 miles @ 25 miles per gallon = 1500/25 = 60 gallons 60 gallons @ 3.50 per gallon = 60*3.50 = 210
12 miles per gallon
Assuming that 25 miles per mile is meant to be 25 miles per gallon(!), 1500 miles @ 25 miles per gallon = 1500/25 = 60 gallons. 60 gallons @ 4.00 per gallon = 60*4 = 240 units of currency.
$300
$240.
$333.33
1500 mi/25mpg *$3.00/gal = $180
At $2.75 per gallon, this trip will cost $147.32
$750.
1500/28 = 53.57 gallons.
I would say it gets about 12 miles per gallon.
The Chevy Silverado 1500 averaged about 16.5 miles per gallon in 2013. Additionally, it averaged 15.6 miles per gallon in 2012 and 15.3 miles per gallon in 2011, so it has improved in the last few years.