Quiz Discussion

The average of two numbers is XY. If one number is X, the other is-

• 1]

  Y/2

• 2]

  Y

• 3]

  2XY - X

• 4]

  X (Y - 1)

The average of runs scored by a cricketer in his 99 innings is 99. How many runs will he have to score to his 100th innings so that his average of runs in 100 innings will become 100 ?

• 1] 100
• 2] 99
• 3] 199
• 4] 101

If the average of x and 1/x(X\( \ne \)0) is M, then the average of x2 and 1/x² is :

• 1] 1 - M2
• 2] 1 - 2M2
• 3] 2M2 - 1
• 4] 2M2 + 1

Four years ago, the average age of a family of four persons was 18 years. During this period, a baby was born. Today if the average age of the family is still 18 years, the age of the baby is

• 1] 1.2 years
• 2] 2 years
• 3] 2.5 years
• 4] 3 years

A school has only four classes that contain 10, 20, 30 and 40 students respectively. The pass percentage of these classes are 20%, 30%, 60% and 100% respectively. Find the pass % of the entire school.

• 1] 56%
• 2] 76%
• 3] 34%
• 4] 66%
• 5] None of these

The average weight of A, B and C is 40 kgs. Weight of C is 24 kgs more than A’s weight and 3 kgs less than B’s weight. What will be the average weight of A, B, C and D, if D weights 15 kgs less than C?

• 1] 42 kgs
• 2] 40 kgs
• 3] 36 kgs
• 4] 38 kgs

A passenger travels from Delhi to Merut at a speed of 30 kmph and return with a speed of 60 kmph. What is the average speed?

• 1] 40
• 2] 45
• 3] 50
• 4] 48

The average of 9 observations was found to be 35. Later on, it was detected that an observation 81 was misread as 18. The correct average of the observation is -

• 1] 28
• 2] 42
• 3] 32
• 4] 45

The average of the largest and smallest 3 digits numbers formed by 0, 2 and 4 would be :

• 1] 312
• 2] 222
• 3] 213
• 4] 303

The average price of 10 books is Rs.12 while the average price of 8 of these books is Rs.11.75. Of the remaining two books, if the price of one book is 60% more than the price of the other, what is the price of each of these two books?

• 1] Rs. 5, Rs.7.50
• 2] Rs. 8, Rs. 12
• 3] Rs. 16, Rs. 10
• 4] Rs. 12, Rs. 14