Instead of using the values {1,2,3,4,5,6} on a dice, suppose a pair of dice have the following {1,2,2,3,3,4} on one die and {1,3,4,5,6,8} on the other. find the probabaility of rolling a sum of 12 with these dice.

Mary and roberto bought identical backpacks at different stores. mary's backpack originally cost $65 and was discounted 25%. roberto's backpack originally cost $75 and was on sale for 30% off on the original price. which backpack was the better buy?