Find the unit price for cheese that is sold in 12-ounce packages priced at $3.84

50r − 6 = 82r − 70. a. r=64 b. r= -64 c.r=2 d.r=-2

lisabon 2012 [21]

Answer:

c

Step-by-step explanation:

Hope this helps.

3 0

3 years ago

Consider a tank used in certain hydrodynamic experiments. After one experiment the tank contains liters of a dye solution with a

Alja [10]

Answer:

t = 460.52 min

Step-by-step explanation:

Here is the complete question

Consider a tank used in certain hydrodynamic experiments. After one experiment the tank contains 200 liters of a dye solution with a concentration of 1 g/liter. To prepare for the next experiment, the tank is to be rinsed with fresh water flowing in at a rate of 2 liters/min, the well-stirred solution flowing out at the same rate.Find the time that will elapse before the concentration of dye in the tank reaches 1% of its original value.

Solution

Let Q(t) represent the amount of dye at any time t. Q' represent the net rate of change of amount of dye in the tank. Q' = inflow - outflow.

inflow = 0 (since the incoming water contains no dye)

outflow = concentration × rate of water inflow

Concentration = Quantity/volume = Q/200

outflow = concentration × rate of water inflow = Q/200 g/liter × 2 liters/min = Q/100 g/min.

So, Q' = inflow - outflow = 0 - Q/100

Q' = -Q/100 This is our differential equation. We solve it as follows

Q'/Q = -1/100

∫Q'/Q = ∫-1/100

㏑Q = -t/100 + c

$Q(t) = e^{(-t/100 + c)} = e^{(-t/100)}e^{c} = Ae^{(-t/100)}\\Q(t) = Ae^{(-t/100)}$

when t = 0, Q = 200 L × 1 g/L = 200 g

$Q(0) = 200 = Ae^{(-0/100)} = Ae^{(0)} = A\\A = 200.\\So, Q(t) = 200e^{(-t/100)}$

We are to find t when Q = 1% of its original value. 1% of 200 g = 0.01 × 200 = 2

$2 = 200e^{(-t/100)}\\\frac{2}{200} = e^{(-t/100)}$

㏑0.01 = -t/100

t = -100㏑0.01

t = 460.52 min

6 0

3 years ago

What happens to the mean of the data set shown below if the number 20 is added to the data set?

defon

Answer:

This shows that the mean increases by 2.95

Step-by-step explanation:

Assume the given data is 2, 5, 6, 8

Mean = 2 +5+6+8/4

Mean = 21/4

Mean = 5.25

If number 20 is added, the data becomes 2, 5, 6, 8, 20

New mean = 2 +5+6+8+20/4

New mean = 41/5

New mean = 8.2

Taking the difference in the mean:

Difference = 8.2 - 5.25

Difference = 2.95

This shows that the mean increases by 2.95

NB: The data used was assumed since we are not given any data in question

4 0

3 years ago

Select an equation that passes through the point (5,7) and is perpendicular to the line x=4

alexandr1967 [171]

y = 7

x = 4 is a vertical line parallel to the y- axis passing through all points with an x- coordinate of 4

A line perpendicular to x = 4 will be a horizontal line parallel to the x- axis with equation y = c where c is the value of the y- coordinate the line passes through.

line passes through (5 , 7) with y- coordinate 7

The equation is therefore y = 7

8 0

3 years ago

Which of the following is a true statement?

aev [14]

Answer:

13/15 > 4/5 is a true stament.

Step-by-step explanation:

The left side is 0.86 repeating turned into a decimal. which means 0.86 is greater than the right which the right is 0.8 turned into a decimal. which in this case this means that the given stament is always true.

4 0

3 years ago