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3 years ago

11

A new type of pump can drain a certain pool in 6 hours. An older pump can drain the pool in 14 hours. How long will it take both

pumps working together to drain the pool?

1 answer:

crimeas [40]3 years ago

3 0

Needs to use reciprocals:

time*(1/6+1/14) = 1 pool,

time = 1/(1/6+1/14) = 84/20 = 21/5 = 4.2 hours

You might be interested in

Angle A and Angle B are vertical angles. If m

damaskus [11]

Answer:

∠B = 17°

Step-by-step explanation:

Vertical angles are congruent, thus

5x + 7 = x + 15 ( subtract x from both sides )

4x + 7 = 15 ( subtract 7 from both sides )

4x = 8 ( divide both sides by 4 )

x = 2

Hence

∠B = 5x + 7 = (5 × 2) + 7 = 10 + 2 = 17°

3 0

3 years ago

Kate gave 5/6 of her CD's to Sue

Alexus [3.1K]

Y=0.72(3) i think tht is the answer

7 0

3 years ago

Need help with 19-20 your suppose to simplify the expression

lesya692 [45]

To solve problem 19, we must remember the order of operations. PEMDAS tells us that we should simplify numbers in parentheses first, exponents next, multiplication and division after that, and finally addition and subtraction. Using this knowledge, we can begin to simplify the problem by working out the innermost set of parentheses:

36 / [10 - (3-1)²]

36 / [10 - (2)²]

Next, we should still simplify what is inside the parentheses but continue to solve the exponents (the next letter in PEMDAS).

36/ (10-4)

After that, we should compute the subtraction that is inside the parentheses.

36/6

Finally, we can solve using division.

6

Now, we can move onto problem 20:

1/4(16d - 24)

To solve this problem, we need to use the distributive property, which allows us to distribute the coefficient of 1/4 through the parentheses by multiplying each term by 1/4.

1/4 (16d-24)

1/4(16d) - 1/4(24)

Next, we can simplify further by using multiplication.

4d - 6

Therefore, your answer to problem 19 is 6 and the answer to problem 20 is 4d -6.

Hope this helps!

3 0

3 years ago

Advertising expenses are a significant component of the cost of goods sold. Listed below is a frequency distribution showing the

Alexxandr [17]

Answer:

Step-by-step explanation:

The table can be computed as:

Advertising Expenses ($ million) Number of companies

25 up to 35 4

35 up to 45 19

45 up to 55 27

55 up to 65 16

65 up to 75 9

TOTAL 75

Let's find the probabilities first:

$P(25 - 35) = P \Big(\dfrac{25-50.93}{10.80}$

For 35 up to 45

$P(35 - 45) = P \Big(\dfrac{35-50.93}{10.80}$

For 45 up to 55

$P(45 - 55) = P \Big(\dfrac{45-50.93}{10.80}$

For 55 up to 65

$P(55 - 65) = P \Big(\dfrac{55-50.93}{10.80}$

For 65 up to 75

$P(65 - 75) = P \Big(\dfrac{65-50.93}{10.80}$

Chi-Square Table can be computed as follows:

Expense No of Probabilities(P) Expe $(O-E)^2$ $\dfrac{(O-E)^2}{E}$

compa cted E (n*p)

nies (O)

25-35 4 0.0612 75*0.0612 = 4.59 0.3481 0.0758

35-45 19 0.2218 75*0.2218 = 16.635 5.5932 0.3362

45-55 27 0.3568 75*0.3568 = 26.76 0.0576 0.021

55-65 16 0.2552 75*0.2552 = 19.14 9.8596 0.5151

65-75 9 0.0839 75*0.0839 = 6.2925 7.331 1.1650

$\sum \dfrac{(O-E)^2}{E}= 2.0492$

Using the Chi-square formula:

$X^2 = \dfrac{(O-E)^2}{E} \\ \\ Chi-square \ X^2 = 2.0942$

Null hypothesis:

$H_o: \text{The population of advertising expenses follows a normal distribution}$

Alternative hypothesis:

$H_a: \text{The population of advertising expenses does not follows a normal distribution}$

Assume that:

$\alpha = 0.02$

degree of freedom:

= n-1

= 5 -1

= 4

Critical value from $X^2 = 11.667$

Decision rule: To reject $H_o \ if \ X^2$ test statistics is greater than $X^2$ tabulated.

Conclusion: Since $X^2 = 2.0942$ is less than critical value 11.667. Then we fail to reject $H_o$

6 0

3 years ago

A motorist took 1.2 hour to travel 96 km how far will he travel in 1 hour

miskamm [114]

Answer:

80km

Step-by-step explanation:

To solve this problem, we need to cross multiply. Lets input the values (1.2, 1.0, 96) as shown below:

$\frac{1.2}{96} = \frac{1.0}{x}$

Next we cross multiply. We multiply 1.2 and x, and we multiply 96 and 1.0.

1.2(x) = 1.2x

96 x 1.0 = 96

Now, lets put the values above back into the equation:

1.2x = 96

Lets solve this equation. First we divide 96 by 1.2.

1. $x = \frac{96}{1.2}$

2. $x = 80$

This means that our answer is 80km.

4 0

3 years ago