1. The
average of first seven prime numbers, rounded off to two decimals is:

(A)
8.27

(B)
7.14

(C)
8.29

(D)
6.00

2. The
average weight of a group of 20 persons was calculated to be 89.4 kg. Later it
was found that one weight was misread as 78 kg instead of 87 kg. What is the
correct average weight?

(A)
88.95 kg

(B)
89.25 kg

(C)
89.55 kg

(D)
89.85 kg

3. Average
age of A, B and C is 84 years. When D joins them the average age becomes 80
years. When E, whose age is 4 years more than D, replaces A then the average of
B,C,D and E becomes 78 years. What is the age of A?

(A)
82 years

(B)
80 years

(C)
78 years

(D)
68 years

4. Average
age of nine numbers is 50. The average of the first five numbers is 54 and that
of the last three numbers is 52. Then the sixth number is-

(A)
30

(B)
34

(C)
24

(D)
44

5. Out
of 40 boys in a class, one boy of height 164 cm leaves the class and another
boy joins thereby the average height of the boys in the class is increased by
0.1 cm from the original average of 160 cm. What is the height of the new boy?

(A)
168 cm

(B)
164 cm

(C)
162 cm

(D)
160.1 cm

6. The
mean of x and 1/x is y. What is the mean of x

^{2}and 1/x^{2 }?
(A)
Y

^{2}
(B)
Y

^{2}-2
(C)
4y

^{2}-2
(D)
2y

^{2}-1
7. The
average of some natural numbers is 15. If 30 is added to the first number and 5
is subtracted from the last number the average becomes 17.5, then the number of
natural numbers token is-

(A)
20

(B)
30

(C)
15

(D)
10

__Answers:__
1. (C)

2. (D)

3. (B)

4. (C)

5. (A)

6. (D)

7. (D)

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