How many pints of pesticide concentrate must be added to a tank of 200 gallons that is being refilled from 75 gallons, using a mix of 2 pints per 50 gallons?

To determine the number of pints of pesticide concentrate needed for a tank of 200 gallons, starting with an existing 75 gallons and using a ratio of 2 pints of concentrate per 50 gallons of water, we first need to calculate the total amount of water present after refilling.

The remaining capacity in the tank after accounting for the 75 gallons is:

200 gallons (total capacity) - 75 gallons (current amount) = 125 gallons to be filled.

Next, we need to determine how many total pints of pesticide concentrate are required for 125 gallons using the specified ratio. Since the mix ratio is 2 pints for every 50 gallons, we first calculate how many 50-gallon increments fit into 125 gallons:

125 gallons ÷ 50 gallons = 2.5 increments.

Now, we multiply the number of increments by the amount of concentrate per increment:

2.5 increments × 2 pints per increment = 5 pints.

Thus, the correct answer is 5 pints, which correctly reflects the amount of pesticide concentrate that must be added for the specified tank capacity and mixing ratio.