Quiz Discussion

A set A consists of integers 27, 28, 30 and 33. If integer k is included in the set, the average of set A will increase by 30%. What is the value of integer k ?

• 1] 68
• 2] 79
• 3] 73.75
• 4] 75.25

30 pens and 75 pencils altogether were purchased for Rs. 510. If the average price of a pencil was Rs. 2, what was the average price of a pen ?

• 1] Rs. 9
• 2] Rs. 10
• 3] Rs. 11
• 4] Rs. 12

The average marks of four subjects is 120. If 33 was misread as 13 during the calculation, what will be the correct average?

• 1] 122
• 2] 120
• 3] 125
• 4] 121

A man travels equal distances of his journey at 40, 30 and 15 km/h. respectively. Find his average speed for whole journey.

• 1] 24
• 2] 25
• 3] 27
• 4] 28

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

If the arithmetic mean of 7, 5, 13, x and 9 is 10, then the value of x is :

• 1] 10
• 2] 12
• 3] 14
• 4] 16

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 average of the first five multiples of 3 is-

• 1] 3
• 2] 9
• 3] 12
• 4] 15

Average of two numbers is 8 and average of other three numbers is 3; the average of the five numbers is :

• 1] 2
• 2] 3
• 3] 5
• 4] 6

The arithmetic mean of the scores of a group of students in a test was 52. The brightest 20% of them secured a mean score of 80 and the dullest 25% a mean score of 31. The mean score of remaining 55% is-

• 1] 45
• 2] 50
• 3] 51.4 approx
• 4] 54.6 approx