Question

The average of 5 whole numbers is 20. When one of the numbers is changed to 18, the new average is now 18. What is the original value of that number?​

Answer 1

Jawaban:

Let's assume the original sum of the 5 whole numbers is "X". Since the average is 20, the sum of the numbers is 5 * 20 = 100.

When one of the numbers is changed to 18, the new sum becomes X - (original value) + 18. The new average is 18, so the new sum is 5 * 18 = 90.

Setting up an equation:

X - (original value) + 18 = 90

Simplifying the equation:

X - (original value) = 90 - 18

X - (original value) = 72

Since the original sum was 100 (X), we can substitute X in the equation:

100 - (original value) = 72

Solving for the original value:

(original value) = 100 - 72

(original value) = 28

Therefore, the original value of the number that was changed to 18 is 28.

Penjelasan dengan langkah-langkah:

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