How do i solve the science club went on a field trip. the numbers paid $60 for transportation plus $15 per ticket to the planetarium. the total for the trip was $120?

Megan and desmond each add the same amount of water to their aquarium megan makes 5 ml of chemical solution with every gallon of water for her aquarium desmond mixed 8 ml of chemical solution for every 2 gallon of the water for his aquarium.