Quiz Discussion

The mean of 25 observations was found to be 78.4. But later on it was found that 96 were misread as 69. The correct means is-

• 1] 76.54
• 2] 78.4
• 3] 79.48
• 4] 81.32

The average height of 30 boys out of a class of 50 is 160 cm. If the average height of the remaining boys is 165 cm, the average height of the whole class (in cm) is :

• 1] 161
• 2] 162
• 3] 163
• 4] 164

Mean of 10 numbers is 30. Later on it was observed that numbers 15, 23 are wrongly taken as 51, 32. The correct mean is :

• 1] 25.5
• 2] 32
• 3] 30
• 4] 34.5

The average of 9 observations was found to be 35. Later on, it was detected that an observation 81 was misread as 18. The correct average of the observation is -

• 1] 28
• 2] 42
• 3] 32
• 4] 45

There are three categories of jobs A, B and C. The average salary of the student who got the job of A and B categories is 26 lakh per annum. The average salary of the students who got the job of B and C category is 44 lakh per annum and the average salary of those students who got the job of A and C categories is 34 lakh per annum. The most appropriate (or closet) range of average salary of all the three categories (if it is known that each student gets only one category of jobs i.e. , A, B and C):

• 1] lies between 30 and 44
• 2] lies between 28 and 34
• 3] lies between 34 and 44
• 4] lies between 27 and 44
• 5] None of these

Find the average of 1.11, 0.01, 0.101, 0.001, 0.11 = ?

• 1] 0.2664
• 2] 0.2554
• 3] 0.1264
• 4] 0.1165

If the average of x and 1/x(X\( \ne \)0) is M, then the average of x2 and 1/x² is :

• 1] 1 - M2
• 2] 1 - 2M2
• 3] 2M2 - 1
• 4] 2M2 + 1

The speed of the train going from Nagpur to Allahabad is 100 km/h while when coming back from Allahabad to Nagpur, its speed is 150 km/h. find the average speed during whole journey.

• 1] 125 km/hr
• 2] 75 km/hr
• 3] 135 km/hr
• 4] 120 km/hr

In a primary school the average weight of male students is 65.9 kg and the average weight of female students is 57 kg. If the average weight of all the students ( both male and female ) is 60.3 kg and the number of male students in the school is 66, what is the number of female students in the school?

• 1] 162
• 2] 168
• 3] 180
• 4] 112

The average of nine number is 50. The average of first five numbers is 54 and that of the last three numbers is 52. Then the sixth number is :

• 1] 30
• 2] 34
• 3] 24
• 4] 44