a trader allows 4% trade discount and makes a profit of 100/3 % on cost price. The price goes up by 25% and he required to increase the trade discount to 10% by what percent the catalogue price has to be increased, so that the trader may make the rate of profit on cost price​

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?