Quiz Discussion

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 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 average age of 20 boys in a class is 12 years. 5 new boys are admitted to the class whose average age is 7 years. The average age of all the boys in the class becomes:

• 1] 8.2 years
• 2] 9.5 years
• 3] 12.5 years
• 4] 11 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 monthly salary of 12 workers and 3 managers in a factory was Rs. 600. When one of the manager whose salary was Rs. 720, was replaced with a new manager, then the average salary of the team went down to 580. What is the salary of the new manager?

• 1] 640
• 2] 690
• 3] 420
• 4] 570

Out of 9 persons, 8 persons spent Rs. 30 on each of their meals. The ninth one spends Rs. 20 more than the average expenditure of all the nine. The total money spent by all of them was

• 1]

  Rs 260

• 2]

  Rs 290

• 3]

  Rs 292.5

• 4]

  Rs 400.5

The average of 11 players of a cricket team is decreased by 2 months when two of them aged 17 years and 20 years are replaced by two new players. The average age of the new players is-

• 1] 17 years 1 month
• 2] 17 years 7 months
• 3] 17 years 11 months
• 4] 18 years 3 months

The mean of 100 observations was calculated as 40. It was founder later on that one of the observation was misread as 83 instead of 53. The correct mean is :

• 1] 39
• 2] 39.7
• 3] 40.3
• 4] 42.7

The average wages of a worker during a fortnight comprising 15 consecutive working days was Rs. 90 per day. During the first 7 days, his average wages was Rs. 87/day and the average wages during the last 7 days was Rs. 92/day. What was his wage on the 8th day?

• 1] 93
• 2] 90
• 3] 92
• 4] 97

A batsman makes a score of 87 runs in the 17th inning and thus increases his average by 3. Find his average after 17th inning.

• 1] 40
• 2] 39
• 3] 52
• 4] 55