Answer: There was 675 gallons left in the tank when she finished.
Step-by-step explanation:
Since we have given that
Total capacity of a tank = 1000 gallons of syrup
Number of cans with syrup filled by Danielle = 65
Number of gallon in each can = 5 gallons
Total number of gallons in 5 cans of syrup is given by

so, Amount of syrup was left in the tank when she finished is given by

Hence, there was 675 gallons left in the tank when she finished.