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3 years ago

What is the answer to 76?

Mathematics

1 answer:

vovangra [49]3 years ago

7 0

Answer:

13.2 minutes or 13 minutes 12 seconds.

Step-by-step explanation:

1. Count how much water drains the first pump every minute. Let the volume of pool be D. Every minute first pump drains D/11 water.

2. Working together(6 minutes) First pump drains 6D/11 water, hence the second pump drains 5D/11 water.

3.Count how much water drains second pump per minute -> (5D/11)/6= 5D/66

4. It takes the second pump 66 minutes to drain pool 5 times, thus it takes 13.2(66/5) minutes to drain the pool, which is 13 minutes 12 seconds.

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A valet makes $56 each day that she works and makes approximately $6 in tips for each car that she parks. If she wants to make a

kirill [66]

She needs to park 16 cars.

$152- 56 = 96

96/6= 16

8 0

2 years ago

Problem PageQuestion Calcium levels in people are normally distributed with a mean of mg/dL and a standard deviation of mg/dL. I

SIZIF [17.4K]

Complete Question

The complete question is shown on the first uploaded image

Answer:

The calcium level that is the borderline between low calcium levels and those not considered low is $c = 8.68$

Step-by-step explanation:

From the question we are told that

The mean is $\mu = 9.5\ mg/dL$

The standard deviation $\sigma = 0.5 \ mg/dL$

The proportion of the population with low calcium level is $p =$ 5% = 0.05

Let X be a X random calcium level

Now the P(X < c) = 0.05

Here P denotes probability

c is population with calcium level at the borderline

Since the calcium level is normally distributed the z-value is evaluated as

$P(Z < \frac{c - \mu}{\sigma } ) = 0.05$

The critical value for 0.05 from the standard normal distribution table is

$t_{0.05} = -1.645$

=> $\frac{c - \mu}{\sigma } = -1.645$

substituting values

$\frac{c - 9.5}{0.5 } = -1.645$

=> $c - 9.5 = -0.8225$

=> $c = 8.68$

6 0

3 years ago

If lin runs 21 laps at the same rate, how long does it take her 25.6 minutes How many laps per minute is that? __ laps

Alex Ar [27]

Answer: 0.82 laps per minute

Step-by-step explanation:

Lin is running 21 laps in 25.6 minutes.

To find out her speed in laps per minute, divide the distance she has ran by the time it took her to run it.

= Distance / time

= 21 / 25.6

= 0.82 laps per minute

6 0

3 years ago

Daine simplified the expression below.

Dennis_Churaev [7]

Answer:

Step-by-step explanation:

8(1 + 2i) - (7 - 3i) = 8*1 + 8*2i + 7*(-1) - 3i*(-1)

= 8 + 16i -7 + 3i

= 8 - 7 + 16i + 3i

= 1 + 19i

Daniel forgot to multiply 2i by 8

3 0

2 years ago

Plz help if you can<br> Thank ya

koban [17]

Answer:

$90\pi$

Step-by-step explanation:

The first step is to find the slant height of the cone. Using the pythagorean theorem, you can find that $\sqrt{12^2+5^2}=13$ cm. Plugging this into the equation, you get $\pi \cdot 5 \cdot 13=90\pi$ . Hope this helps!

3 0

2 years ago