66.
The average age of 8 men is increased by 2
years when two of them whose ages are 21 years and 23 years are replaced by two
new men. The average age of the two new men is:
a)
22 years
b)
24 years
c)
28 years
d)
30 years
67.
The average of five consecutive numbers is n.
if the next two numbers are also included, the average will.
a)
Remain the same
b)
Increase by 1
c)
Increase by 1.4
d)
Increase by 2.
68.
A cricketer has a certain average for 10
innings. In the eleventh inning, he scored 108 runs, thereby increasing his
average by 6 runs. His new average is:
a)
48 runs
b)
52 runs
c)
55 runs
d)
60 runs
69.
A cricketer whose bowling average is 12.4 runs
per wicket takes 5 wickets for 26 runs and thereby decreases his average by
0.4. The number of wickets taken by him till the last match was:
a)
64
b)
72
c)
80
d)
85
70.
A team of 8 persons joins in a shooting
competition. The best marksman scored 85 points. If he had scored 92 points, the
average score for the team would have been 84. The number of points, the team
scored was:
a)
588
b)
645
c)
665
d)
672
ANSWERS
66.D
67.B
68.A
69.D
70.C
SOLUTION
66.
Total age increased =(8 x 2.5) kg =20 kg.
Sum
of ages of two new men = (21 + 23 + 16) years = 60 years.
Average
age of two new men = (60 /2) years = 30 years.
67.
Let five consecutive numbers be x, X + 1, X + 2,
X + 3 and X + 4.
Their
average = 5X + 10 / 5 = (X +2).
Average
of 7 numbers = (5X + 10) + (x + 5) +(X +6) / 7 = 7x + 21 / 7 = (x + 3).
So,
the average increased by 1.
68.
Let average for 10 innings be X. then,
10x
+ 108 / 11 = x + 6 11 X + 66 = 10x 108
x = 42.
New
average = (x + 6) = 48 runs.
69.
Let the number of wickets taken till the last
match is X. then.
12.4x
+ 26 / X+ 5 = 12 12.4x + 26 = 12x +
60 0,4x = 34 x = 34 / 0. 4 = 340/4 = 85.
70.
Let the
total score be x.
X
+ 92 – 85 / 8 = 84 x + 7 = 672 x = 665.
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