Can someone help me with this

If 30 lb of rice and 30 lb of potatoes cost ? $27.60? , and 20 lb of rice and 12 lb of potatoes cost ? $15.04? , how much will 10 lb of rice and 50 lb of potatoes? cost?

1.based of the diagrams what is the the value of x? 2.how would you verify your answer for x

Luis has a cooler filled with cans of soda. for every 5 cans of coke there are 3 cans of sprite. if there are 25 cans of coke, how mant cans of sprite are there?