Quiz Discussion

The average of 6 observations is 45.5. If one new observation is added to the previous observations, then the new average becomes 47. The new observation is :

• 1] 58
• 2] 56
• 3] 50
• 4] 46

If the arithmetic mean of 0, 5, 4, 3 is a, that of -1, 0, 1, 5, 4, 3 is b and that of 5, 4, 3 is c, then the relation between a, b, and c is

• 1] a = b = c
• 2] a : b : c = 3 : 2 : 4
• 3] 4a = 5b = c
• 4] a + b + c = 12

A cricketer whose bowling average is 12.4 runs per wicket takes 5 wickets for 26 runs and thereby decreased his average by 0.4. The number of wickets taken by him the last match was-

• 1] 64
• 2] 72
• 3] 80
• 4] 85

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

A library has an average of 510 visitors on Sundays and 240 on other days. The average number of visitors per day in a month of 30 days beginning with a Sunday is

• 1]

  285

• 2]

  276

• 3]

  280

• 4]

  290

A has 50 coins of 10 paise denominations. While B has 10 coins of 50 paise denominations. C has 20 coins of 25 paise denominations while D has 25 coins of 20 paise denominations. The average number of paise per person is :

• 1] 450 paise
• 2] 500 paise
• 3] 550 paise
• 4] 650 paise

The present age of a father is 3 years more than three times the age of his son. Three years hence, father's age will be 10 years more than twice the age of the son. The father's age is :

• 1] 33 years
• 2] 39 years
• 3] 45 years
• 4] 40 years

In 2011, the arithmetic mean of the annual incomes of Ramesh and Suresh was Rs. 3800. The arithmetic mean of the annual incomes of Suresh and Pratap was Rs. 4800, and the arithmetic mean of the annual incomes of Pratap and Ramesh was Rs. 5800. What is the arithmetic mean of the incomes of the three?

• 1] Rs. 4000
• 2] Rs. 4200
• 3] Rs. 4400
• 4] Rs. 4800

A student finds the average of 10, 2 digits numbers. If the digits of one of the numbers interchanged, the average increases by 3.6. The difference between the digits of the 2 digits number is :

• 1] 4
• 2] 3
• 3] 2
• 4] 5

The average of the first 100 positive integers is-

• 1] 49.5
• 2] 50.5
• 3] 51
• 4] 100