1answer.
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
mestny [16]
3 years ago
5

One pipe can fill a swimming pool in 8 hours. Another pipe takes 12 hours. How long will it take to fill the pool if both pipes

are used simultaneously?
Mathematics
1 answer:
Nookie1986 [14]3 years ago
5 0
For 4 h and 48 min. The first pipe fills the whole pool for 8 hours so from here we see that it fills 1/8 each hour. The second pipe fills it for 12 hours so it fills 1/12 each hour. Now both of them together fill 1/8 + 1/12 of the pool each hour. That equals: 1st pipe 3/24 of the pool each hour and the 2nd pipe 2/24 of the pool each hour. So, the two pipes together fill 3/24 + 2/24 each hour. That's 5/24 of the pool each hour.
1st hour: 5/24
2nd hour: 10/24
3rd hour: 15/24
4th hour: 20/24
And we need 4/24 more. So, if 5/24 is 1 h, then 1/24 is (60 minutes/5) 12 minutes. We need 4*1/24 and that is 12 minutes * 4 and that is 48 minutes.

So, they will fill the pool for 4 h and 48 min.
You might be interested in
Help?? Thanks so much
Ira Lisetskai [31]
A..........duh just read the sides of the graph
6 0
3 years ago
What foes the graph of profits as a function of the number of hats sold look like?​
natita [175]
The answer is D i think
7 0
3 years ago
Two angles are complementary. One has a measure of 25 degrees. What is the measure of the other angle?
Pani-rosa [81]

Answer:

65 degrees

Step-by-step explanation:

Since complementary angles are 2 angles that add up to 90 degrees, all you have to do is subtract 25 from 90.

When you do that you get 65.

Example: 90 - 25 = 65

8 0
3 years ago
I have 100 items of product in stock. The probability mass function for the product's demand D is P(D=90)=P(D=100)=P(D=110)=1/3.
masya89 [10]

Answer:

The probability mass function for the items sold is

P_X(k) = \left \{ {\frac{1}{3} \, \, \, {k=90} \atop \, \frac{2}{3} \, \, \, {k=100}} \right.

The mean is 96.667

The variance is 22.222

b) The probability mass function for the unfilled demand due to lack of stock is

P_Y(k) = \left \{ {\frac{2}{3} \, \, \, {k=0} \atop \, \frac{1}{3} \, \, \, {k=10}} \right.

The mean is 3.333

The variance is 33.333

Step-by-step explanation:

If the demand is higher than 100, then you will sell 100 items only. Thus, there is a probability of 1/3+1/3 = 2/3 that you will sell 100 items, while there is a probability of 1/3 that you will sell 90.

The probability mass function for the items sold is

P_X(k) = \left \{ {\frac{1}{3} \, \, \, {k=90} \atop \, \frac{2}{3} \, \, \, {k=100}} \right.

The mean is 1/3 * 90 + 2/3 * 100 = 290/3 = 96.667

The variance is V(X) = E(X²)-E(X)² = (1/3*90² + 2/3*100²) - (290/3)² = 200/9 = 22.222

b) If order to be unfilled demand, you need to have a demand of 110, which happens with probability 1/3. In that case, the value of the variable, lets call it Y, that counts the amount of unfilled demand due to lack of stock is 110-100 = 10. In any other case, the value of Y is 0, which would happen with probability 1-1/3 = 2/3. Thus

P_Y(k) = \left \{ {\frac{2}{3} \, \, \, {k=0} \atop \, \frac{1}{3} \, \, \, {k=10}} \right.

The mean is 2/3 * 0 + 1/3 * 10 = 10/3 = 3.333

The variance is 2/3*0² + 1/3*10² = 100/3 = 33.333

4 0
3 years ago
Find the answer <br><br> A.<br><br> B.<br><br> C.
KATRIN_1 [288]
B. 68
I use the formula A= bh/2 it’s the same thing
8x17 = 136
136/2 = 68
6 0
3 years ago
Other questions:
  • I am having trouble with this question and it is really giving me a headache ​
    12·2 answers
  • .Adam is 3 times as old as his sister Naya , in 4 years he will be twice as old as Naya , how old are Adam and Naya now ?
    5·1 answer
  • -x ≥ -3 somebody help me
    12·1 answer
  • A crate is 3/4 yard long and 2/3 yard wide the crate is also 2 feet tall what is the area of the top of the crate
    14·1 answer
  • The box plots below show student grades on the most recent exam compared to overall grades in the class:
    8·1 answer
  • Slope is used for which of the following situations? Slope is used to determine if lines are parallel. Slope is used to determin
    8·1 answer
  • Can someone help plz?????
    7·2 answers
  • 1. A grocery store has 120 bottles of spring water in stock. The store
    11·1 answer
  • A six sided die is tossed. Determine the odds against rolling a 3.<br><br> The odds are :
    12·1 answer
  • Help ASAP help help help
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!