a2zinterviews

1.	There are two sections A and B of a class, consisting of 36 and 44 students respectively. If the average weight of sections A is 40 kg and that of sections b is 35 kg. Find the average weight of the whole class?
	A.  36.25
	B.  37.25
	C.  38.35
	D.  39.25

Solution

Total weight of(36+44)Students = (36x40+44x35)Kg = 2980 kg. Average weight of the whole class = (2980 / 80) = 37.25.

2.	A batsman makes a score of 87 runs in the 17th inning and thus increases his averages by 3. Find his average after 17th inning?
	A.  19
	B.  29
	C.  39
	D.  49

Solution

Let the average after 17th inning = x. Then, average after 16th inning = (x - 3) Average =16 (x-3)+87 = 17x or x=(87-48) = 39.

3.	The average age of 36 students in a group is 14 years. When teacher's age is included to it, the average increases by one. What is the teacher's age in years?
	A.  31
	B.  41
	C.  51
	D.  61

Solution

Age of the teacher = (37 x 15 - 36 x 14) = 51 years.

4.	David obtained 76, 65, 82, 67 and 85 marks (out in 100) in English, Mathematics, Physics, Chemistry and Biology. What are his average marks?
	A.  65
	B.  69
	C.  72
	D.  75

Solution

Average = (76+65+82+67+85 / 5) =(375 / 5) = 75.

5.	The average of 20 numbers is zero. Of them, at the most, how many may be greater than zero?
	A.  0
	B.  1
	C.  10
	D.  19

Solution

Average of 20 numbers = 0 Sum of 20 numbers =(0 x 20) =0. It is quite possible that 19 of these numbers may be positive and if there sum id a, then 20th number is (-a).