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The question for the day is a Math question from the topic Averages.

Question 1

If the mean of numbers 28, x, 42, 78 and 104 is 62, then what is the mean of 128, 255, 511, 1023 and x?

1. 395
2. 275
3. 355
4. 415
5. 365

The correct choice is (A) and the correct answer is 395.

Explanatory Answer

The average (arithmetic mean) of the 5 numbers 28, x, 42, 78 and 104 is 62.

Therefore, the sum of these 5 numbers is 62 * 5 = 310

i.e., 28 + x + 42 + 78 + 104 = 310

Hence, x = 310 - 252 = 58.

The average of 128, 255, 511, 1023 and x == 395

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