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Pages in a Book

JavaScriptHardnumbersmathvalidation

Instructions

Suppose that you add all of the page numbers in a book. If the total is 21, the book could only have 6 pages because 1 + 2 + 3 + 4 + 5 + 6 = 21. If I had said the total were 25, that would be impossible because the next number in the series is 28 (21 + 7).

Create a function that, given the total number of pages as an argument, returns true if it is a valid total and false if it is not.

Can you devise a solution that is more efficient than simply adding consecutive integers as I did above?

Examples

pagesInBook(5) ➞ false

pagesInBook(4005) ➞ true

pagesInBook(9453) ➞ true

Notes

N/A

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Walks through the solution with reasoning and edge cases.
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