Quiz Discussion

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

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 mean high temperature of the first four days of a week is 25°C whereas the mean of the last four days is 25.5°C. If the mean of the whole week is 25.2°C then the temperature of the 4th day is :

• 1] 25°C
• 2] 25.2°C
• 3] 25.6°C
• 4] 25.5°C

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

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 present age of a father is 3 years more than three times the age of his son. Three years hence, father's age will be 10 years more than twice the age of the son. The father's age is :

• 1] 33 years
• 2] 39 years
• 3] 45 years
• 4] 40 years

If the arithmetic mean of 0, 5, 4, 3 is a, that of -1, 0, 1, 5, 4, 3 is b and that of 5, 4, 3 is c, then the relation between a, b, and c is

• 1] a = b = c
• 2] a : b : c = 3 : 2 : 4
• 3] 4a = 5b = c
• 4] a + b + c = 12

Find the average of the following sets of scores:385, 441, 876, 221, 536, 46, 291, 428

• 1] 221
• 2] 403
• 3] 428
• 4] 536
• 5] None of these

The average age of an adult class is 40 years. 12 new students with an average age of 32 years join the class, thereby decreasing the average by 4 years. The original strength of the class was-

• 1] 10
• 2] 11
• 3] 12
• 4] 15

A has 50 coins of 10 paise denominations. While B has 10 coins of 50 paise denominations. C has 20 coins of 25 paise denominations while D has 25 coins of 20 paise denominations. The average number of paise per person is :

• 1] 450 paise
• 2] 500 paise
• 3] 550 paise
• 4] 650 paise