If an aircraft treats 14 acres per tank and applies at a volume of 1.5 pints per acre, how many pints should be put in the spray tank?

To determine how many pints should be placed in the spray tank, we should first calculate the total number of acres that the aircraft can treat with a full tank, which is given as 14 acres. Since the aircraft applies a treatment volume of 1.5 pints per acre, we need to multiply the number of acres by the application rate.

This calculation is as follows:

Total volume needed = Acres treated × Volume per acre

Total volume needed = 14 acres × 1.5 pints per acre

Total volume needed = 21 pints

Thus, to treat 14 acres at the application rate of 1.5 pints per acre, the spray tank should contain a total of 21 pints of the product. This matches the correct answer.