The average of 23 numbers is 51. The average of first 12 numbers is 49 and the average of last 12 numbers is 54. If the twelfth number is removed, then the average of the remaining numbers (correct to two decimal places) is:
Answer & explanation
Correct answer: option 2
Sum of 23 numbers = 23 x 51 = 1173
Sum of 1st 12 numbers = 12 x 49 = 588
Sum of last 12 numbers = 12 x 54 = 648
Twelfth number = (588 + 648) - 1173 = 63
If twelfth number is removed, Sum of remaining numbers = 1173 - 63 = 1110
Average of remaining number = \(\frac{1110}{22}\) = 50.45