Quiz Discussion

The average of marks in Mathematics for 5 students was found to do 50. Later, it was discovered that in the case of one student the marks 48 were misread as 84. The correct average is :

• 1] 40.2
• 2] 40.8
• 3] 42.8
• 4] 48.2

The average sale of car dealership was 15 cars per week. After a promotional scheme the average sale increased to 21 cars per week. The percentage increased in the sale of cars was-

• 1]

  39.33%

• 2]

  40%

• 3]

  \(42\frac{6}{7}\)%

• 4]

  140%

The average temperature for Wednesday, Thursday and Friday was 40°C. The average for Thursday, Friday and Saturday was 41° C. If temperature on Saturday was 42° C, what was the temperature on Wednesday?

• 1] 39° C
• 2] 44° C
• 3] 38° C
• 4] 41° C

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 reduction in the speed of an engine is directly proportional to the square of the number of bogies attached to it. The speed of the train is 100 km/hr when there are 4 bogies and 55 kmph when there are 5 bogies. What is the maximum number of bogies that can be attached to the train so that it can move?

• 1]

  4

• 2]

  5

• 3]

  6

• 4]

  7

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

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

10 years ago, the average age of a family of 4 members was 24 years. Two children having been born (with age difference of 2 years), the present average age of the family is again 24 years. Then the present age of the youngest child is:

• 1]

  1 years

• 2]

  2 years

• 3]

  3 years

• 4]

  4 years

Find the average increase rate, if increase in the population in the first year is 30% and that in the second year is 40%.

• 1] 41%
• 2] 56%
• 3] 40%
• 4] 38%
• 5] 39%

The average age of group of 20 girls is 15 years and that of another group of 25 boys it is 24 years. The average age of the two groups mixed together is :

• 1] 19.5 yearas
• 2] 20 years
• 3] 21 yearas
• 4] 21.5 years