18 is what percent of 20?

Roger could feed 5 walruses with 4 kilograms of fish. how many walruses could he feed with 7.2 kilograms of fish?

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?

52 cm radius = diameter = area = circumference = circumfer