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Four whole numbers are each rounded to the nearest 10
The sum of the four rounded numbers is 90
What is the maximum possible sum of the original four numbers?
2000

1 Answer

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Final answer:

To find the maximum possible sum of the original four numbers when rounded to the nearest 10, we need to consider rounding up and rounding down. The maximum sum would be 100.


Step-by-step explanation:

To find the maximum possible sum of the original four numbers, we need to consider the rounding process. If a number is rounded down, it means it is closer to the previous multiple of 10. Conversely, if a number is rounded up, it is closer to the next multiple of 10.

In this case, let's assume the four rounded numbers are a, b, c, and d. We want to find the maximum possible sum of the original four numbers: x + y + z + w.

If a and b are rounded down, c and d are rounded up. The closest multiple of 10 to a is a - 5, and the closest multiple of 10 to b is b - 5. Similarly, the closest multiple of 10 to c is c + 5, and the closest multiple of 10 to d is d + 5.

Since the sum of the rounded numbers is 90, we can write the following equation: (a - 5) + (b - 5) + (c + 5) + (d + 5) = 90.

Simplifying the equation, we get: a + b + c + d = 100.

Therefore, the maximum possible sum of the original four numbers is 100.

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