Tanisha bought 2 skirts and 3 pairs of pants for $220. A week later she bought 1 skirt and 3 pairs of pants, at the same prices, for $185. How much is each skirt?

What is the axis of symmetry of the function f(x)=-(x+ 9)(x-21)

How many kilograms of a 5% salt solution and how many kilograms of a 15% salt solution must be mixed together to make 45kg of an 8% salt solution?

Gravel is being dumped from a conveyor belt at a rate of 25 ft3/min, and its coarseness is such that it forms a pile in the shape of a cone whose base diameter and height are always equal. how fast is the height of the pile increasing when the pile is 14 ft high? (round your answer to two decimal places.) ft/min