Gillian has two goats. She feeds them hay and grain. Gillian buys both kinds of food on April 30. The amount of grain that gillian has left, as a function of time, is modeled by this graph. Gillian feeds the goats the same amount of hay each day. On may 3, she has 72 pounds of hay left. On May 5, she has 60 pounds of hay left. Based on the information and the graph provided, how many pounds of hay does gillian most likely have left on the day that she has most likely 3 pounds of grain left? Provide evidence to support your answer. Include algebraic representations for each situation as part of your support.