answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Liula [17]
2 years ago
5

A cistern can be completely drained by a pipe in 6 hours. It can be filled by two pipes in 4 hours and 5 hours, respectively. Ho

w many hours will the empty cistern take to fill if all the pipes are running?
If x is the time to fill it, which of the following equations could be used to solve for t?

4x + 5x - 6x = 1
15x + 12x - 10x = 60
4x + 5x = 20
Mathematics
1 answer:
boyakko [2]2 years ago
6 0
X/4 +x/5 -x/6=1
make the denominator the same: 
15x/60 +12x/60 -10x/60=1
17x=60
x=60/17=3.53 hours

the second choice is the correct answer.
You might be interested in
How many 4/5 cup servings are in 4/9 of a cup of yogurt
kolbaska11 [484]
For this question, you need to understand how to divide fractions.First we line up our fractions appropriately:
4/9 ÷ 4/5 = ?         (You want to divide 4/9 by 4/5)
4/9 × 5/4 = ?         (Now we use the reciprocal of 4/5 and multiply instead of divide)
4 x 5 = 20 and 9 x 4 = 36.       (Cross multiply.)
20/36 = 5/9.           (Simplify to lowest terms.)
So, 4/9 divided by 4/5 is 5/9!But 5/9 is more than 4/9, so the answer is 0 :PCorrect me if I'm wrong.
5 0
2 years ago
Read 2 more answers
John deposited $2860 in a bank that pays 9% interest, compounded monthly. Find the amount he will have at the end of 3 years.
kati45 [8]
Please see figure for the answer.

3 0
2 years ago
Read 2 more answers
A study of immunizations among school‑age children in California found that some areas had rates of unvaccinated school‑age chil
Rom4ik [11]

Answer:

Probability that none of the 20 children in such a classroom would be unvaccinated is 0.055.

Step-by-step explanation:

We are given that a classroom of 20 children in one such area where 13.5% of children are unvaccinated.

If there are no siblings in the classroom, we are willing to consider the vaccination status of the 2020 unrelated children to be independent.

The above situation can be represented through binomial distribution;

P(X=r) = \binom{n}{r} \times p^{r} \times (1-p)^{n-r} ; x = 0,1,2,3,......

where, n = number of trials (samples) taken = 20 children

            r = number of success = none of the 20 children

            p = probability of success which in our case is probability that

                   children are unvaccinated, i.e; p = 13.5%

<u><em>Let X = Number of children that are unvaccinated</em></u>

So, X ~ Binom(n = 20, p = 0.135)

Now, Probability that none of the 20 children in such a classroom would be unvaccinated is given by = P(X = 0)

           P(X = 0)  =  \binom{20}{0} \times 0.135^{0} \times (1-0.135)^{20-0}

                          =  1\times 1 \times 0.865^{20}

                          =  0.055

<em>Hence, the probability that none of the 20 children in such a classroom would be unvaccinated is 0.055.</em>

8 0
2 years ago
A bucket that has a mass of 30 kg when filled with sand needs to be lifted to the top of a 30 meter tall building. You have a ro
Rom4ik [11]

Answer:

765 J

Step-by-step explanation:

We are given;

Mass of bucket = 30 kg

Mass of rope = 0.3 kg/m

height of building= 30 meter

Now,

work done lifting the bucket (sand and rope) to the building = work done in lifting the rope + work done in lifting the sand

Or W = W1 + W2

Work done in lifting the rope is given as,

W1 = Force x displacement

W1 = (30,0)∫(0.2x .dx)

Integrating, we have;

W1 = [0.2x²/2] at boundary of 30 and 0

W1 = 0.1(30²)

W1 = 90 J

work done in lifting the sand is given as;

W2 = (30,0)∫(F .dx)

F = mx + c

Where, c = 30 - 15 = 15

m = (30 - 15)/(30 - 0)

m = 15/30 = 0.5

So,

F = 0.5x + 15

Thus,

W2 = (30,0)∫(0.5x + 15 .dx)

Integrating, we have;

W2 = (0.5x²/2) + 15x at boundary of 30 and 0

So,

W2 = (0.5 × 30²)/2) + 15(30)

W2 = 225 + 450

W2 = 675 J

Therefore,

work done lifting the bucket (sand and rope) to the top of the building,

W = 90 + 675

W = 765 J

5 0
2 years ago
There were 125 females and 100 males present at the high school pep rally. Find the ratio of males to the total number of people
riadik2000 [5.3K]
Total number of people = 125 + 100 = 225

Number of males = 100

Set as ratio

100:225

Simplify to 4:9 (can not simplify further without having decimals but you can’t have half a person)
5 0
2 years ago
Other questions:
  • Consider the function represented by the equation y-6x-9=0. Which answer shows the equation written in function notation with x
    12·2 answers
  • a coast Guard ship patrols an area of 125 square miles. the are the ship patrols is a square. about how long is each side of the
    12·1 answer
  • Find the area of the following circle. (Round answer to the nearest whole number.) Circumference = 280 cm. (Hint: Find r from C
    9·2 answers
  • 6 tractors take 10days to collect the harvest. How long would it take 18 tractors to do the same amount of work?
    5·1 answer
  • The diagram shown here represents
    15·2 answers
  • A research submarine descends 65 meters per minutes to a depth of 4485 m, conducts experiments, and then ascends at a rate of 65
    9·2 answers
  • A survey finds that 48% of people identify themselves as fans of professional football, 12% as fans of car racing, and 9% as fan
    14·2 answers
  • A university warehouse has received a shipment of 25 printers, of which 10 are laser printers and 15 are inkjet models. If 6 of
    9·1 answer
  • Researchers studied the mean egg length​ (in millimeters) for a particular bird population. After a random sample of​ eggs, they
    5·1 answer
  • What’s the x value of PR=9x-31 and QR=43?
    15·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!