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1 . |
If mean of y and
$1\over y$
is M, then what is the mean of
$y^3$and $1\over y^3$?
a. $M(M^2-3)\over3$ , b.$M^3$ , c.$M^3$-3 , d. M( $4M^2$-3) |
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Answer & Explanation
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Answer : Option
D
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| Explanation : |
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2 . |
From a series of 50 observations, an observation with
value 45 is dropped but the mean remains the same. What
was the mean of 50 observations? |
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Answer & Explanation
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Answer : Option
C
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| Explanation : |
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Let the observation mean = x
∴ Sum of 50 observations = 50x
According to question
∴ $50x-45\over49$ x
=> 50x-45=49x
∴ x= 45 |
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3 . |
Read the following information
carefully to answer the questions that follow.
The average age of 6 persons living in a house is 23.5 years. Three
of them are majors and their average age is 42 years.
The difference in ages of the three minor children is same
What is the mean of the ages of minor children? |
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Answer & Explanation
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Answer : Option
C
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| Explanation : |
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Total age of six persons = 23.5 × 6 = 141 years
Total age of three major persons = 42 × 3 = 126 years
∴ Total age of three minor children = 141 – 126 = 15 years
The difference in ages of the three minor children is same.
Therefore, we take ages may be:
5, 5, 5; 3, 5, 7; 2, 5, 8 and 1, 5, 9
In all the cases, median will be 5 years
Mean age of minor children = $15\over3$ = 5 years |
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4 . |
Read the following information
carefully to answer the questions that follow.
The average age of 6 persons living in a house is 23.5 years. Three
of them are majors and their average age is 42 years.
The difference in ages of the three minor children is same
What is the median of the ages of minor children? |
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Answer & Explanation
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Answer : Option
B
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| Explanation : |
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Total age of six persons = 23.5 × 6 = 141 years
Total age of three major persons = 42 × 3 = 126 years
∴ Total age of three minor children = 141 – 126 = 15 years
The difference in ages of the three minor children is same.
Therefore, we take ages may be:
5, 5, 5; 3, 5, 7; 2, 5, 8 and 1, 5, 9
In all the cases, median will be 5 years.
Median age of minor children = 5 years |
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5 . |
In how many ways can a committee of 4 people be chosen
out of 8 people ? |
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Answer & Explanation
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Answer : Option
C
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| Explanation : |
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Required number of ways
= $^8$$c_4$ = $8!\over4!(8-X4)!$ = $5×6×7×8\over1×2×3×4$ = 70 |
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6 . |
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Answer & Explanation
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Answer : Option
D
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| Explanation : |
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Male Engineers + Male Designers
40% of (18% of 10500) + 65% of (16% of 10500)
Female Engineers + Female Designers
= 60% of (18% of 10500) + 35% of (16% of 10500)
∴ Required ratio = (40 × 18)
+ (65 × 16) : (60 × 18 + 35 × 16)
= (720 + 1040) : (1080 + 560)
= 1760 : 1640 = 44 : 41 |
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7 . |
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Answer & Explanation
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Answer : Option
C
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| Explanation : |
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Required % = $19\over21$ X 100 = 90%
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8 . |
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Answer & Explanation
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Answer : Option
D
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| Explanation : |
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% of female professionals =
= [20% of 21% + 60% of 18% + 40% of 11% + 80% of 15%
+ 40% of 19% + 35% of 16%]
$1\over100$
= [420 + 1080 + 440 +1200 + 760 + 560]%
= $4460\over100$%
= 44.6%
∴ % of male professionals
= 100% – 44.6% = 55.4%
∴ Required diff
= (55.4 – 44.6)% of 10500
= 10.8% of 10500
= 10.8 × 105 = 1134 |
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9 . |
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Answer & Explanation
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Answer : Option
D
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| Explanation : |
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Required %
=
$20 of 21\over89of 15$x 100%= $20 X21\over89X15$x 100%
$420\over12$= 35%
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10 . |
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Answer & Explanation
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Answer : Option
A
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| Explanation : |
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Required ratio = $60x11\over20x15$=11.5 |
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