Credit you make a profit?

4sentences over a chronicle of a teen killer

In 1919, the temperance movement finally succeeded. they secured ratification of a constitutional amendment (the that banned alcoholic beverages. prohibition began with the 1920 passage of the which enforced the amendment.

Case # 51173878 weighs 814 pounds; case # 51173981 weighs 803 pounds; case # 51174058 weighs 817 pounds; case 51174178 weighs 815 pounds; case # 51174248 weighs 817 pounds; case # 51174495 weighs 781 pounds; case # 51174577 weighs 828 pounds. what are the case #'s of the two cases that weigh the same amount?