Diferent dimensions of rectangular prism with surface area of 96

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?

Me i’m stuck on all these questions besides the two bottom ones

Student representatives surveyed their classmates on their preference of a school mascot for a new school. the results are shown in the table below. which pair of samples seems most representative of student preference?