Average

1.A batsman makes a score of 85 runs in the 16th inning and thus increases his average by 3. Find his average after 16th inning? A)36 B)37 C)39 D)40 Answer : Option D Explanation: Let the average after 16th inning = x Then average after 15th inning = x - 3 =>therefore 15(x-3)+85 = 16x =>therefore x = 85 - 45 = 40 2.The average of four consecutive odd numbers is 40. What is the difference between the highest and lowest numbers : A)5 B)7 C)6 D)8 Answer : Option C Explanation: Let the numbers be x, x + 2, x + 4, x + 6 . Then [x + (x + 2) + (x + 4) + (x + 6) ] / 4 = 40. or 4x + 12 = 148 or x = 37. So, required difference = (37 + 6) - 37 = 6 3. The average of 5 consecutive numbers is 17. The largest of these numbers is : A)16 B)14 C)15 D)18 Answer : Option C Explanation: Let the numbers be x, x + 1, x + 2, x + 3, x + 4 Then (x + (x + 1) + (x + 2) + (x + 3) + (x + 4) ) / 5 = 17 or 5x + 10 = 85 or 5x = 75 or x =15. Latest number = x + 4 = 19. 4.The mean of 50 observations was 36. It was found later that an observation 48 was wrongly taken as 23. The corrected new mean is : A)34 B)36.5 C)37 D)38 Answer : Option B Explanation: Correct Sum = (36 * 50 + 48 - 23) = 1825. Correct mean = = 1825/50 = 36.5

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