Y is inversely proportional to a^3 When a=2, y=20

a is directly proportional to x
When x=4, a=20

Find a formula for y in terms of x.
Give your answer in its simplest form.

The dance committee of pine bluff middle school earns $72 from a bake sale and will earn $4 for each ticket they sell to the spring fling dance. the dance will cost $400 write an inequality to determine the number, t of tickets the committee could sell to have money left over after they pay for this year's dance. what is the solution set of the inequality?

Round to the nearest ten thousandth.i dont get this

Abarge can safely haul no more than 400 tons across the river. the barge has an empty weight of 24 tons. the average weight of the railroad cars is 4 tons each.bhow many railroad cars can the barge haul?