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3 years ago

A train 375 m long is running at a speed of 45 km/hr.how long will it take to pass a single post

Mathematics

1 answer:

Kruka [31]3 years ago

4 0

we know that

The time it takes for the train to pass a single post is equal to the time it takes for the train to pass its length.

the length of the train is-----> 375 m

convert to Km

1 Km =1,000 m

375 m=375/1,000=0.375 Km

the speed of the train is 45 km/hour

by proportion

$\frac{1}{45}\frac{hour}{Km} =\frac{x}{0.375}\frac{hour}{Km}\\ \\45*x=0.375\\ \\ x=0.375/45\\ \\x=0.0083\ hours$

convert to minutes

1 hour=60 minutes

0.0083 hours=0.0083*60=0.5 minutes

convert to seconds

1 minute=60 sec

0.5 minutes=0.5*60=30 sec

therefore

the answer is

30 seconds

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ANSWER

$14 \: ft$

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3 years ago

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Answer:

- 24x + 9

Step-by-step explanation:

Differentiate each term using the power rule

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Given

f(x) = - 12x² + 9x, then

f'(x) = (2 × - 12)x + (9 × 1) $x^{0}$ = - 24x + 9

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4 years ago

You have a biased coin for which p(h)=pp(h)=p. you toss the coin 2020 times. what is the probability that you observe 88 heads a

Nat2105 [25]

The question describes a binomial probability with p(h) = p, then p(t) = 1 - p and number of trials (n) = 20

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Part A:

The probability of observing 8 heads and 12 tails is given by:

$P(8)=\, ^{20}C_8p^8(1-p)^{20-8}=\, ^{20}C_8p^8(1-p)^{12}$

Part B:

You observe more than 8 heads and more than 8 tails, when you observe 9 heads and 11 tails, 10 heads and 10 tails, and 11 heads and 9 tails.

Therefore, the probability of observing more than 8 heads and more than 8 tails is given by:

$P(9)+P(10)+P(11) \\ \\ =\, ^{20}C_9p^9(1-p)^{20-9}+\, ^{20}C_{10}p^{10}(1-p)^{20-10}+\, ^{20}C_{11}p^{11}(1-p)^{20-11} \\ \\ =\, ^{20}C_9p^9(1-p)^{11}+\, ^{20}C_{10}p^{10}(1-p)^{10}+\, ^{20}C_{11}p^{11}(1-p)^{9}$

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3 years ago

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3 years ago

A bulletin board has a perimeter of 200 inches. Which equation expresses the area A(w) of the bulletin board as a function of it

o-na [289]

Answer: A(W) = 100W - $W^{2}$

Step-by-step explanation:

The formula for calculating the perimeter is given as :

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Dividing through by 2 , we have

100 = L + W

Make L the subject of the formula ;

L = 100 - W

The formula for the area is given as Length x width , substituting the values , we have :

A = LW , since , L = 100 - W , we have

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Therefore :

A(W) = 100W - $W^{2}$

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3 years ago