Multiple choice

Average of 5 numbers is 45. Sum of 4 numbers is 125. What will be the fifth number?

  1. 80

  2. 100

  3. 105

  4. 90

  5. 40
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B Correct answer
Explanation

The sum of 5 numbers is 5 * 45 = 225. If the sum of 4 numbers is 125, the fifth number is 225 - 125 = 100.

AI explanation

Using the basic average formula, the total sum of all 5 numbers is 5 multiplied by 45, which equals 225. Since the sum of the first 4 numbers is 125, the fifth number is 225 minus 125. This makes the fifth number equal to 100.

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