If b is inversely proportional to c, and b is 5 when c is 12, find b when c = 20

here is the link for the answer

https://socratic.org/questions/suppose-c-is-inversely-proportional-to-the-square-of-d-if-c-6-when-d-3-find-the-#506800

lockers 1, 4, 9, 16, 25, 40, and 49 are open

i ran through it by the other answer is wrong