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1. If the product of 3 consecutive integers is 120, then the sum of the integers is----
- A. 9
- B. 9
- C. 9
- D. 9
Answer: Option B
Explanation:
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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