Math Chapter Wise

EnglishDSSSB PGT 2021

Q81.6 coins are tossed 6,400 times. What is the probability of getting 6 heads, x times?

A100x 1 e x − Be–100x Cxe–100x D100 100x e x! −

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EnglishDSSSB PGT 2021

Q82.If X1 and X2 are two independent variables and Y = a1 X1 + a2 X2 then E (Y) is _______

Aa1E(X1) + a2 E(X2) Ba1 X1 + a2 X2 CX1 + X2 Da1 X2 + a2 X1

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EnglishDSSSB PGT 2021

Q83.A manufacturer of steel blades found 5 percent of its blades defective. He sells blades in packets, each containing 5 blades. The probability that a packet contains one defective blade is

Ae–0.25 B0.25.e–0.25 C0.5 D0.25

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EnglishDSSSB PGT 2021

Q84.Marks of a chemistry test follow a normal distribution with a mean of 65 and a standard deviation of 12. Approximately what percentage of the students have scored below 50?

A89 percent B18 percent C11 percent D15 percent

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EnglishDSE TGT 2019

Q85.The mean and variance of a random variable X having a binomial distribution are 4 and 2 respectively. What is the value of P(X = 1)?

A1/16 B1/8 C1/32 D1/4

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EnglishDSE TGT 2019

Q86.The probability that A speaks the truth is 3/5 and probability that B speaks the truth is 3/4. What is the probability that they contradict each other when they are asked to speak a fact?

A4/5 B7/20 C3/20 D9/20

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EnglishOAVS TGT 2021

Q87.An insect is able to go inside a hole 60% time of his trials, What is the probability of his success 2 times out of 5 trials to enter into the hole?

A144/625 B154/625 C625/144 D720/625

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EnglishOAVS TGT 2021

Q88.Two fair dice are rolled simultaneously. What is the probability that the sum on the faces obtained is 6?

A5/36 B1/6 C1/9 D1/12

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EnglishOAVS TGT 2021

Q89.If mean and median of a data is 28 and 20, respectively, find its mode.

A4 B5 C6 D3

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EnglishOAVS TGT 2021

Q90.If a random variable increases when other random variable decreases, their correlation coefficient will be:

A0.5 B0.7 C–0.5 D0

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EnglishOAVS TGT 2021

Q91.If random variable and corresponding probability of an experiment are tabulated as given, find the mathematical expectation E(2X). Random variable (x) –1 0 1 2 Probability P(x) ¼ 1/2 1/8 1/8

A1/8 B1/6 C1/3 D1/4

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EnglishOAVS TGT 2019

Q92.The mean and variance of 8 observations and 6 and 8 respectively. If some of these observations are 3, 5, 6, 8, 9, 10 then the remaining two observations are:

A1, 5 B1, 6 C2, 4 D3, 1

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EnglishOAVS TGT 2019

Q93.If mean is 11 and median is 13 then value of mode is:

A15 B11 C17 D13

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EnglishOAVS TGT 2019

Q94.If x is a binomial variant with p = 1/5, for the experiment of 50 trials, then the standard deviation is equal to:

A2 2 B3 2 C2 D3

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EnglishOAVS TGT 2019

Q95.If the slope of the regression line is calculated to be 2.5 and the intercept 16 then the value of Y when X is 4 is:

A29 B18 C33 D26

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EnglishOAVS TGT 2019

Q96.If Y = –10X and X = –0.1Y, then correlation coefficient r is equal to:

A0 B–1 C0.2 D0.5

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EnglishOAVS TGT 2019

Q97.If in a class, 40% of the student study math and science and 60% of the students study math, then the probability of a students studying science given that he/she is already studying math is:

A0.47 B0.67 C0.63 D0.55

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EnglishOAVS TGT 2019

Q98.If a gymnastics coach has 77 gymnasts, their height are as follows (in cm): 172, 173, 164, 178, 168, 169, 173, 172, 173, 164, 178, 168, 169, 173 then the average deviation of this data is:

A2.73 B2.43 C3.73 D3.43

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EnglishOAVS TGT 2019

Q99.How many number of six digits which can be formed from the digits 4, 5, 6, 7, 8, 9 with no digits being repeated and are not divisible by 5?

A690 B540 C600 D780

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EnglishOAVS TGT 2019

Q100.For a certain type of mobiles, the duration of time between charges of the battery is normally distributed with a mean of 50 hours and a standard deviation of 15 hours. A person owns one of these mobiles and wants to know the probability that the duration of the time will be between 50 and 70 hours is: (Given (1.33) 0.9082, (0) 0.5)

A0.4082 B–0.5 C–0.4082 D0.5

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