Quiz Discussion

Find the average of all prime numbers between 30 and 50.

• 1]

  37.8

• 2]

  38.9

• 3]

  39.8

• 4]

  42.8

Distance between two stations A and B is 778km. A train covers the journey from A to B at 84 km per hour and returns back to A with a uniform speed of 56 km per hour. Find the average speed of train during the whole journey.

• 1]

  60 km/hr

• 2]

  30.5 km/hr

• 3]

  57 km/hr

• 4]

  67.2 km/hr

The average of 20 students is 12 years, if the teacher's age is included, average increases by one. The age of the teacher is:

• 1] 30 years
• 2] 33 years
• 3] 28 years
• 4] 35 years

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

The average age of husband and his wife was 23 years at the time of their marriage. After five tears they have a one-year old child. The average age of the family of three, when the child was born, was-

• 1] 23 years
• 2] 24 years
• 3] 18 years
• 4] 20 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

The average age of a class is 15.8 years. The average age of the boys in the class is 16.4 years while that of the girls is 15.4 years. What is the ratio of boys to girls in the class?

• 1]

  1:2

• 2]

  2:3

• 3]

  3:4

• 4]

  3:5

The average age of 30 students of a class is 14 years 4 months. After admission of 5 new students in the class the average becomes 13 years 9 months. The youngest one of the five new students is 9 years 11 months old. The average age of the remaining 4 new students is :

• 1] 10 years 4 months
• 2] 12 years 4 months
• 3] 11 years 2 months
• 4] 13 years 6 months

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

a, b, c, d, e, f, g are consecutive even numbers. j, k, l, m, n are consecutive odd numbers. The average of all the numbers is :

• 1]

  \(3\left( {\frac{{a + n}}{2}} \right)\)

• 2]

  \(\left( {\frac{{1 + d}}{2}} \right)\)

• 3]

  \(\left( {\frac{{a + b + m + n}}{4}} \right)\)

• 4]

  \(3\left( {\frac{{j + c + n +g}}{4}} \right)\)