Quiz Discussion

The average weight of 21 boys was recorded as 64 kg. If the weight of the teacher was added, the average increased by 1 kg. What was the teacher’s weight?

• 1] 86 kg
• 2] 64 kg
• 3] 72 kg
• 4] 84 kg

A shop of electronic goods is closed on Monday. The average daily sales for remaining six days of a week is Rs. 15,640 and the average sale of Tuesday to Saturday is Rs. 14,124. The sales on Sunday is -

• 1] Rs. 20,188
• 2] Data inadequate
• 3] Rs. 23,220
• 4] Rs. 21,704

The average age of 30 students is 9 years. If the age of their teacher is included, the average age becomes 10 years. The age of the teacher (in years) is :

• 1] 27
• 2] 31
• 3] 35
• 4] 40

The average weight of 8 men is increased by 1.5 kg when one of the men, who weight 65 kg is replaced by a new man. The weight of the new man is-

• 1] 70 kg
• 2] 74 kg
• 3] 76 kg
• 4] 77 kg

There are 30 students in a class. The average age of first 10 students is 12.5 years. The average age of the remaining 20 students is 13.1 years. The average age (in years) of the students of the whole class is :

• 1] 12.5 years
• 2] 12.7 years
• 3] 12.8 years
• 4] 12.9 years

The arithmetic mean of the scores of a group of students in a test was 52. The brightest 20% of them secured a mean score of 80 and the dullest 25% a mean score of 31. The mean score of remaining 55% is-

• 1] 45
• 2] 50
• 3] 51.4 approx
• 4] 54.6 approx

The average of the first five multiples of 9 is:

• 1] 20
• 2] 27
• 3] 28
• 4] 30

A cricketer scored some runs in his 21st innings, as a result, his average runs increased by 3. If the present average run is 40, how many runs he scored in the final innings?

• 1] 103
• 2] 100
• 3] 85
• 4] 82

The average age of three boys is 15 years. If their ages are in ratio 3 : 5 : 7, the age of the youngest boy is

• 1] 21 years
• 2] 18 years
• 3] 15 years
• 4] 9 years
• 5] 12 years

The mean of 100 items was 46. Later on it was discovered that an item 16 was misread as 61 and another item 43 was misread as 34. It was also found that the number of item was 90 and not 100. Then what is the correct mean ?

• 1] 50
• 2] 50.7
• 3] 52
• 4] 52.7