# Average- Aptitude Questions and Answers

 Among five people with monthly income of Rs. 14000, Rs. 25000, Rs. 15000, Rs. 18000 and Rs.49000, how many will have income less than the mean income of the five people? A) 1 B) 2 C) 3 D) 4 Correct Answer : 3 Explanation :Avrage value = (14000+25000+15000+18000+49000) / 5 = 24200 3 person has less income than mean income The average of the marks obtained by three girls in a test was twice the average of the marks obtained by eight boys in that test. If the total marks obtained by all these examinees was 168, find the average marks each of the girls obtained ? A) 25 B) 12 C) 24 D) 14 Correct Answer : 24 Explanation :let avg marks of boys= X number of boys = 8 sum of marks of boys =8X as is given, avg marks of girls = 2X number of girls =3 sum of marks of girls= 6X Now, total sum of marks obtained = 168 = 8X+6X X = 168/14 = 12 avg marks of girls = 2X =2*12 =24 The mean of 100 students marks was found to be 40. it was found later that a mark 53 was read as 83. the correct mean is? A) 40.30 B) 40.70 C) 39.40 D) 39.70 Correct Answer : 39.70 Explanation :As given, mean marks of 100 students = 40 mean = sum of observation / no of observations Sum of marks = 100 * 40 = 4000 Given that one observation is misread as 53 instead of 83 Hence after replacement, correct sum of observations = 4000 - 83 + 53 = 3970 Correct mean =sum of new observation / no of observations = 3970/100 = 39.7 Find the average. 62, 54, 44, 36, 28 & 22 A) 39 B) 40 C) 41 D) 42 Correct Answer : 41 Explanation :Average = Sum of all the observations / Number of observation Average = (62 + 54 + 44 + 36 + 28 + 22) / 6 = 41 So the average of the given numbers is 41. In the world cup, Yuvraj has a batting average of 65 in 7 matches till semi-final. How much should Yuvraj score in the 8th match ie the final match to get a batting average of 85? A) 230 B) 215 C) 220 D) 225 Correct Answer : 225 Explanation :Sum of values = Average of values * Number of values So, Total score of Yuvraj in 7 matches = 65 * 7 = 455 Total score of Yuvraj after 8th match (final) = 85 * 8 = 680 Score in the 8th match = Total score after 8th match - Total score in 7 matches =680 – 455 =225 Therefore Yuvraj should score 225 in the 8th match to get a batting average of 85. The average mark of 50 students is 75. If the marks obtained by one of the student had been written as 36 instead of 86, then the corrected average of marks is: A) 51 B) 76 C) 36 D) 61 Correct Answer : 76 Explanation :Sum of values = Average of values × Number of values The total marks obtained by 50 students = 75 * 50 = 3750 Marks of one student is written as 36 instead of 86. Actual marks = 3750 + (86 – 36) =3750 + 50 =3800 Hence correct average = Actual marks/total number of students =3800/50 =76 The sum of two numbers is 15 and their geometric mean is 20% lower than their arithmetic mean. Find the numbers? A) 11,4 B) 12,3 C) 13,2 D) 10,5 Correct Answer : 12,3 Explanation :Let the numbers be x and y. x+y = 15, or y = 15 - x ...…(1) GM= (xy)^1/2 AM = (x+y)/2 = 15/2 As given, GM = AM - 20% of AM GM = AM( 1 - 20/100) (xy)^1/2 = [(x+y)/2]*80/100 (xy)^1/2 = 15/2 * 80/100 = 6 Square both sides xy =6^2 = 36 y = 36/x ...…(2) Equate (1) and (2) 15-x = 36/x, or x^2–15x+36=0 (x-12)(x-3) = 0 So x = 12 or 3 and y = 3 or 12. So the two numbers are 3 and 12.