If the product of 3 consecutive integers is 120, then the sum of the integers is --

If the product of 3 consecutive integers is 120, then the sum of the integers is -- Correct Answer 15

Let the first integer be x - 1. Then the next two integers would be x and x + 1. So: (x - 1)× x × (x + 1) = 120 = > (x² - 1)x = 120 = > x³ - x = 120 ∴x = 5 , Check 5³ - 5 = 125 - 5 = 120. So, x = 5. The other two numbers are 4 and 6 which are equal to x - 1 and x + 1 respectively. Now the total of these numbers is 3x = 3×5 = 15.
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