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

The average age of husband, wife and their child 3 years ago was 27 years and that of wife and the child 5 years ago was 20 years. The present age of the husband is :

• 1] 40 years
• 2] 35 years
• 3] 50 years
• 4] None of the options

A train covers the first 16 km at a speed of 20 km per hour another 20 km at 40 km per hour and the last 10 km at 15 km per hour. Find the average speed for the entire journey.

• 1]

  24 km

• 2]

  26 km

• 3]

  21 km

• 4]

  km

The average (arithmetic mean) of 330, 360 and 390 is :

• 1]

  \({3^{27}} + {3^{57}} + {3^{87}}\)

• 2]

  \({3^{29}} + {3^{59}} + {3^{89}}\)

• 3]

  \({3^{60}}\)

• 4]

  \({3^{177}}\)

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

Find the average of 1.11, 0.01, 0.101, 0.001, 0.11 = ?

• 1] 0.2664
• 2] 0.2554
• 3] 0.1264
• 4] 0.1165

The mean of 100 observations was calculated as 40. It was founder later on that one of the observation was misread as 83 instead of 53. The correct mean is :

• 1] 39
• 2] 39.7
• 3] 40.3
• 4] 42.7

The average age of four boys A, B, C and D is 5 years and the average age A, B, D, E is 6 years. C is 8 years old. The age of E is (in years) :

• 1] 12
• 2] 13
• 3] 14
• 4] 15

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

A student finds the average of 10 positive integers. Each integer contains two digits. By mistake, the boy interchanges the digits of one number say ba for ab. Due to this, the average becomes 1.8 less than the previous one. What was the difference of the two digits a and b?

• 1] 8
• 2] 6
• 3] 2
• 4] 4