Quiz Discussion

Five years ago the average age of A, B, C, D was 45 years. By including X the present average of all the five is 49 years. Them the present age of X is-

• 1] 40 years
• 2] 45 years
• 3] 48 years
• 4] 64 years

The average of the ages of Sumit, Krishna and Rishabh is 43 and the average of the ages of Sumit, Rishabh and Rohit is 49. If Rohit is 54 years old, what is Krishna’s age?

• 1] 24 years
• 2] 36 years
• 3] 45 years
• 4] Cannot be determined
• 5] None of these

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

The average of the largest and smallest 3 digits numbers formed by 0, 2 and 4 would be :

• 1] 312
• 2] 222
• 3] 213
• 4] 303

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

• 1]

  37.8

• 2]

  38.9

• 3]

  39.8

• 4]

  42.8

From a class of 42 boys, a boy aged 10 years goes away and in his place, a new boy is admitted. If on account of this change, the average age of the boys in that class increases by 2 months, the age of the newcomer is :

• 1] 19 years
• 2] 17 years
• 3] 10 years 6 months
• 4] 12 years 2 months

The average of five numbers is 7. If three new numbers would be added, then the new average comes out to be 8.5. What is the average of those three new numbers ?

• 1] 9
• 2] 10.5
• 3] 11
• 4] 11.5

3 years age, the average age of a family of 5 members was 17 years. A baby having been born, the average age of the family is same today. The present age of the baby is :

• 1]

  1 years

• 2]

  \(1\frac{1}{2} \)years

• 3]

  2 years

• 4]

  3 years

The average income of A, B and C is Rs. 12,000 per month and average income of B, C and D is Rs. 15,000 per month. If the average salary of D be twice that of A, then the average salary of B and C is in Rs. :

• 1] 8,000
• 2] 18,000
• 3] 13,500
• 4] 9,000

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