21. The average of six numbers is X and the
average of three of these is Y.If the average of the remaining three is z, then
A. x =
y + z B.
2x = y + z
C. x =
2y + 2z D. None of these
22.
A car owner buys petrol at Rs.7.50, Rs. 8 and Rs. 8.50 per litre for three
successive years. What approximately is the average cost per litre of petrol if
he spends Rs. 4000 each year?
A. Rs. 7.98 B. Rs. 8
C. Rs. 8.50 D. Rs. 9
23.
In Arun's opinion, his weight is greater than 65 kg but less than 72 kg. His
brother doest not agree with Arun and he thinks that Arun's weight is greater
than 60 kg but less than 70 kg. His mother's view is that his weight cannot be
greater than 68 kg. If all are them are correct in their estimation, what is
the average of different probable weights of Arun?
A. 67 kg. B. B.68 kg.
C. 69 kg. D. D.Data inadequate
E. None of these
24.
The average weight of A, B and C is 45 kg. If the average weight of A and B be
40 kg and that of B and C be 43 kg, then the weight of B is:
A. 17 kg B.20 kg
C. 26 kg D.31 kg
25. Nine persons went to a hotel for taking
their meals. Eight of them spent Rs.12 each on their meals and the ninth spent
Rs.8 more than the average expenditure of all the nine. What was the total
money spent by them.
A.Rs. 115
B.Rs. 116
C.Rs. 117
D.Rs. 118
View Answer With Explanation
26. A library has an average of 510 visitors
on sundays and 240 on other days. The average number of visitors per day in a
month of 30 days beginning with a sunday is
A. 250 B.
276
C.
280 D. 285
27. David
obtained 76, 65,
82, 67 and
85 marks (out
of 100) in
English, mathematics, physics,
chemistry and biology. What are his average marks?
A.65
B.69
C.75
D.None of above
View Answer With Explanation
28.
The average weight of 16 boys in a class is 50.25 kg and that of the remaining
8 boys is 45.15 kg. Find the average weights of all the boys in the class.
A. 47.55 kg B.48 kg
C. 48.55 kg D.49.25 kg
29.
A library has an average of 510 visitors on Sundays and 240 on other days. The
average number of visitors per day in a month of 30 days beginning with a
Sunday is:
A. 250 B.276
C. 280 D.285
30.
If the average marks of three batches of 55, 60 and 45 students respectively is
50, 55, 60, then the average marks of all the students is:
A. 53.33 B.54.68
C.55 D.None of these
