Question

Rosamaria is setting up a 20 gallon saltwater fish tank that needs to have a salt content of 3.5%. If rosamaria has water that has 2.5% salt and water that has 3.7% salt, how many gallons of the water with 3.7% salt content should rosamaria use?

Answer 1

She should use 0.74 gallons you have to take 20 and timed it by 3.7 % and thats how you get to see whats left that she need.