Quiz Discussion

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

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

Average of a, b, and c is 11; average of c, d and e is 17; average of e and f is 22 and average of e and c is 17. Find out the average of a, b, c, d, e and f.

• 1]

  \(15\frac{2}{3}\)

• 2]

  \(18\frac{1}{2}\)

• 3]

  \(16\frac{1}{2}\)

• 4]

  None of these

In a boat there are 8 men whose average weight is increased by 1 kg when 1 man of 60 kg is replaced by a new man. What is weight of new comer?

• 1] 70 kg
• 2] 66 kg
• 3] 68 kg
• 4] 69 kg

Total expenses of a boarding house are partly fixed and partly varying linearly with the number of boarders. The average expense per boarder is Rs. 700 when there are 25 boarders and Rs. 600 when there are 50 boarders. What is the average expense per boarder when there are 100 boarders?

• 1] Rs. 540
• 2] Rs. 550
• 3] Rs. 570
• 4] Rs. 580

There are two sections A and B of a class, consisting of 36 and 44 students' respectively. If the average weight of section A is 40kg and that of section B is 35kg, find the average weight of the whole class.

• 1] 30 kg
• 2] 35 kg
• 3] 42.5 kg
• 4] 37.25 kg

Find the average of the first 40 natural numbers.

• 1]

  21

• 2]

  20.5

• 3]

  21.5

• 4]

  None Of These

After replacing an old member by a new member, it was found that the average age of five members of a club is the same as it was 3 years ago. What is the difference between the ages of the replaced and the new member?

• 1] 2 years
• 2] 4 years
• 3] 8 years
• 4] 15 years

There were 35 students in a hostel. Due to the admission of 7 new student, the expenses of the mess were increased by Rs. 42 per day, while the average expenditure per head diminished by Re 1. What was the original expenditure of the mess?

• 1]

  432

• 2]

  442

• 3]

  420

• 4]

  415

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