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Challenges | HackerRank Print the total number of challenges created by hackers. www.hackerrank.com Problem Julia asked her students to create some coding challenges. Write a query to print the hacker_id, name, and the total number of challenges created by each student. Sort your results by the total number of challenges in descending order. If more than one student created the same number of ch..

Ollivander's Inventory | HackerRank Help pick out Ron's new wand. www.hackerrank.com Problem Harry Potter and his friends are at Ollivander's with Ron, finally replacing Charlie's old broken wand. Hermione decides the best way to choose is by determining the minimum number of gold galleons needed to buy each non-evil wand of high power and age. Write a query to print the id, age, coins_needed, a..