Melinda uses 3 cups of salt for every 5 cups of flour to make modeling clay. what is the unit rate for the relationship if there is 1 cup of flour?

One cell phone plan charges $20 per month plus $0.15 per minute used. a second cell phone plan charges $35 per month plus $0.10 per minute used. write and solve an equation to find the number of minutes you must talk to have the same cost for both calling plans.