Andrea's fish tank holds 30 gallons of water. andrea estimates that every inch of a fish's length requires a gallon of water. she wants to purchase some corydoras that are 2 inches long, angelfish that are 5 inches long, and fancy guppies that are 3 inches long. write an equation for the situation.

x + y + z = 30
2x + 5y + 3z = 300
x + y + z = 100
2x + 5y + 3z = 30

Nthe opening scene of the movie raiders of the lost ark, indiana jones replaces a golden statue with a bag of sand. the platform on which the statue is placed is designed to detect the mass of the statue. if the bag of sand has a different mass than the statue, then a mechanism triggers and destruction ensues. the density of gold is about 20\text{ g/cm}^320 g/cm 3 20, space, g, slash, c, m, start superscript, 3, end superscript. the density of sand can be estimated at 2.5\text{ g/cm}^32.5 g/cm 3 2, point, 5, space, g, slash, c, m, start superscript, 3, end superscript. the gold statue can be modeled as a cylinder with height 25\text{ cm}25 cm25, space, c, m and radius 8\text{ cm}8 cm8, space, c, m. in terms of \piπpi, what is the mass of sand indiana jones needs to avoid triggering the mechanism?