Quiz Discussion

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

• 1]

  40

• 2]

  39

• 3]

  52

• 4]

  55

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

If the mean of 4 observations is 20, when a constant 'c' is added to each observation, the mean becomes 22. The value of c is :

• 1]

  6

• 2]

  -2

• 3]

  2

• 4]

  4

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

Out of 20 boys, 6 are each of 1 m 15 cm height, 8 are of 1 m 10 cm and rest of 1 m 12 cm. The average height of all of them is :

• 1] 1 m 12.1 cm
• 2] 1 m 21.1 cm
• 3] 1 m 21 cm
• 4] 1 m 12 cm

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

In an exam, the average marks obtained by Jhon in English, Math, Hindi and Drawing were 50. His average mark in Maths, Science, Social Studies and Craft were 70. If the average mark in all seven subjects is 58, his score in Maths was -

• 1] 50
• 2] 52
• 3] 60
• 4] 74

The average age of the boys in a class is 16 years and that of the girls is 15 years. The average age for the whole class is-

• 1] 15 years
• 2] 15.5 years
• 3] 16 years
• 4] Cannot be computed with the given information

Average weight of 25 students of a class is 50 kg. If the weight of the class teacher is included , the average is increased by 1 kg. The weight of the teacher is ?

• 1] 76 kg
• 2] 77 kg
• 3] 74 kg
• 4] 75 kg

A cricketer had a certain average of runs for his 64 innings. In his 65th innings, he is bowled out for no score on his part. This brings down his average by 2 runs. His new average of runs is :

• 1] 130
• 2] 128
• 3] 70
• 4] 68