One grade of tea costing $3.20 per pound is mixed with another grade costing $2.00 per pound to make 20 pounds of a blend that will sell for $2.72 per pound. How much of the $3.20 grade is needed? Formulate an equation and then solve it to find how much of the $3.20 grade is needed. Show all of your work.

Sophia wrote an equation to represent the revenue of a movie theater for one day. she let x represent the number of child tickets sold and y represents the nunver of adult tickets sold. if a child ticket cost $4, an adult ticket cost $6, and the total revenue for the daybwas $420, which equation could sophia use to represent the number of chikd and adult tickets that were sold?