Answer:
$64.3
Step-by-step explanation:
Given the following
Total distance = 900miles
Rate per gallon = 21miles per gallon
rate = distance/time
Get the number of gallons used;
Number of gallons used = 900/21
Number of gallons = 42.857gallons
If coost of 1 gallon is $1.50
42.857gallons will cost 42.857 * 1.50
42.857gallons will cost $64.3
Hence he should budget $64.3 for the trip