Quiz Discussion

The mean high temperature of the first four days of a week is 25°C whereas the mean of the last four days is 25.5°C. If the mean of the whole week is 25.2°C then the temperature of the 4th day is :

• 1] 25°C
• 2] 25.2°C
• 3] 25.6°C
• 4] 25.5°C

The average of 10 items was found to be 80 but while calculating, one of the items was counted as 60 instead of 50. Then the correct average would have been :

• 1] 69
• 2] 79.25
• 3] 79
• 4] 79.5

The average age of 24 boys and their teacher is 15 years. When the teacher's age is excluded, the average age decreases by 1 year. The age of the teacher is :

• 1] 38 years
• 2] 39 years
• 3] 40 years
• 4] 41 years

The average of 6 numbers is 7. The average of three numbers of them is 5. What will be the average of remaining numbers?

• 1] 15
• 2] 30
• 3] 9
• 4] 42

The average monthly salary of 660 workers in a factory is Rs. 380. The average monthly salary of officers is Rs. 2100 and the average monthly salary of the other workers is Rs. 340. Find the number of other workers.

• 1] 645
• 2] 650
• 3] 640
• 4] 642

The average age of four boys A, B, C and D is 5 years and the average age A, B, D, E is 6 years. C is 8 years old. The age of E is (in years) :

• 1] 12
• 2] 13
• 3] 14
• 4] 15

The average weight of a class of 24 students is 35 kg. If the weight of the teacher be included, the average rises by 400 g. The weight of the teacher is -

• 1] 45 kg
• 2] 50 kg
• 3] 53 kg
• 4] 55 kg

Ajay working in a Cellular company as a salesman. His monthly salary is Rs. 200. But he gets bonus as per given rule. If he sells sim cards of Rs. X then his bonus will be   . In the first quarter of the year his average sale was Rs. 3000 per month. In the next 5 five month his average sale was Rs. 5000 per month and for next four month his average sale was Rs. 8000 per month. What is the average earning per month for the whole year?

• 1] Rs. 3350
• 2] Rs. 3610
• 3] Rs. 3750
• 4] Rs. 3560
• 5] None of these

If 25a + 25b = 115, what is the average of a and b?

• 1] 2.5
• 2] 3.4
• 3] 4.5
• 4] 4.6
• 5] None of these

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