Answer:
The answer is C. How many 3/4 -pound molds are in 1/3 pound of sand?
Answer:
The volume of the concentrated 80 gallons mixture is 20 gallons
The volume of water in the 80 gallons mixture is 60 gallons
Step-by-step explanation:
The given parameters are;
The content of Container A = The cleaner
The concentration of the cleaner = 20% solution
The content of Container B = Pure water
The concentration of the desired solution = 5%
The volume of the required solution = 80 gallons
Let x represent the volume of the concentrated solution and y represent the volume of water in the 80 gallons mixture
Therefore, we have;
20/100 × x + y×0 = 5/100×80
x + y = 80
y = 80 - x
20/100 × x + (80 - x)×0 = 5/100×80
0.2·x = 4
x = 4/0.2 = 20
x = 20 gallons
y = 80 - x = 80 - 20 = 60
y = 60 gallons
The volume of the concentrated solution (80 gallons mixture) = x = 20 gallons
The volume of water in the 80 gallons mixture = y = 60 gallons.
Answer: a. 0.6759 b. 0.3752 c. 0.1480
Step-by-step explanation:
Given : The long-distance calls made by the employees of a company are normally distributed with a mean of 6.3 minutes and a standard deviation of 2.2 minutes
i.e.
minutes
minutes
Let x be the long-distance call length.
a. The probability that a call lasts between 5 and 10 minutes will be :-

b. The probability that a call lasts more than 7 minutes. :
![P(X>7)=P(\dfrac{X-\mu}{\sigma}>\dfrac{7-6.3}{2.2})\\\\=P(Z>0.318)\ \ \ \ [z=\dfrac{X-\mu}{\sigma}]\\\\=1-P(Z](https://tex.z-dn.net/?f=P%28X%3E7%29%3DP%28%5Cdfrac%7BX-%5Cmu%7D%7B%5Csigma%7D%3E%5Cdfrac%7B7-6.3%7D%7B2.2%7D%29%5C%5C%5C%5C%3DP%28Z%3E0.318%29%5C%20%5C%20%5C%20%5C%20%5Bz%3D%5Cdfrac%7BX-%5Cmu%7D%7B%5Csigma%7D%5D%5C%5C%5C%5C%3D1-P%28Z%3C0.318%29%5C%5C%5C%5C%3D1-0.6248%5C%20%5C%20%5C%20%5C%20%5B%5Ctext%7Bby%20z-table%7D%5D%5C%5C%5C%5C%3D0.3752)
c. The probability that a call lasts more than 4 minutes. :

Answer:
$1290
Step-by-step explanation:
1250x3.2%=40
1250+40=1290