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4 years ago

12

The water in a public swimming pool can be emptied through a single pipe in 6 hours. When this pipe is closed, a second pipe can

fill the pool in 4 hours. If both pipes are accidentally left open, how long will it take to fill the pool?

1 answer:

iogann1982 [59]4 years ago

3 0

Answer: npo

Step-by-step explanation:

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Let X equal the number of flips of a fair coin that are required to observe

Nataliya [291]

Answer:

(a) I attached a photo with the diagram.

(b) $f(x) = \big( \frac{1}{2} \big)^{x-1}$

(c) 1/4

(d) 4

(e) $k^2/2$

Step-by-step explanation:

(a) I attached a photo with the diagram.

(b) The easiest way to think about this part is in terms of combinatorics. Think about it like this.

To begin with, look at the three each level of the three represents a possible outcome of throwing the coin n-times. If you throw the coin 3 times at the end in total there are 8 possible outcomes. But The favorable outcomes are just 2.

1 - Your first outcome is HEADS and all the others are different except the last one.

2 - Your first outcome is TAILS and all the others are different except the last one.

Therefore the probability of the event is

$f(x) = P(X=x) = \frac{2}{2^x} = \frac{1}{2^{x-1}} = \big( \frac{1}{2} \big)^{x-1}$

(c)

P(X = 0) = 0 because it is not possible to have two consecutive tails or heads.

$E(X > 4) = 1 - P(X \leq 3) = 1 - ( P(X = 0 ) + P(X = 1) + P(X = 2) + P(X = 3))\\= 1 - ( \frac{1}{2} + \frac{1}{4} ) = \frac{1}{4}$

(d)

Remember that this is a geometric distribution therefore

$E[X] = p/(1-p)$ , in this case $p = 1/2$ so $E[X] = 1$ and

$E[X+1]^2 = ( E[X] +1 )^2 = (1+1)^2 = 2^2 = 4$

Also

(e)

This is a geometric distribution so its variance is

$Var(X) = \frac{1-p}{p^2} = 1/2 / 1/4 = 1/2$

And using properties of variance

$Var(kX - k ) = Var(kX) = k^2 var(X) = k^2 /2$

3 0

4 years ago

I really need help please

Akimi4 [234]

Answer:

Benidorm quiz

1. Where is Benidorm holiday resort located?

JORDAN

2. What is the average temperature of Benidorm in summer?

26 C

3. Before 1950s Benidorm was a small ___FISHING______ village.

4. Why did the town council encourage tourism in Benidorm?

TO VISIT BENIDORM

5. How many hotels were found in Benidorm in 1959?

6. Explain package holidays as they were used in Benidorm

7. Give three reasons why Benidorm is an excellent tourist resort

(a)

(b)

©

8. State four tourist attractions at Benidorm

Step-by-step explanation:

Benidorm quiz

1. Where is Benidorm holiday resort located?

JORDAN

2. What is the average temperature of Benidorm in summer?

26 C

3. Before 1950s Benidorm was a small ___FISHING______ village.

4. Why did the town council encourage tourism in Benidorm?

TO VISIT BENIDORM

5. How many hotels were found in Benidorm in 1959?

6. Explain package holidays as they were used in Benidorm

7. Give three reasons why Benidorm is an excellent tourist resort

(a)

(b)

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8. State four tourist attractions at Benidorm

8 0

3 years ago

Alex Ar [27]

Answer:

that's easy

Step-by-step explanation:

first we should check the 5 cm in scale .

Then we can easily draw 5 cm in side and diagonal.

hope it's clear to you.

5 0

3 years ago

1. If 40% of a number is 56, what was the original number?

Setler79 [48]

Answer:

140

I am not completely sure but what i did was

56/? = 40/100

56*100

5600/40

140

7 0

3 years ago

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One fluid ounce of liquid is equivalent to two cups of liquid<br> TRUE OR FALSE

OleMash [197]

Definitely false. A liquid ounce is much smaller than one cup of the same liquid, let alone two cups of the liquid.

4 0

3 years ago

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