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3 years ago

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The ratio of men to women in a room is 3:4. Eight women enter the room, no men enter the room and none of the original people in

the room leave. If the ratio of men to women in the room is now 3:5, how many people are now in the room?
Please answer this if only you know how to do this. Please!

2 answers:

vampirchik [111]3 years ago

8 0

There are 64 people in the room.

Since the ratio for women increases 1 when 8 women enter the room, for every time there is 1 in the ratio there are 8 people. That means that originally you have to do 3x8 and 4x8. You get 24 and 32 which equals 56. Then when 8 more women enter the room, you get 64.

White raven [17]3 years ago

3 0

Answer:

64

Step-by-step explanation:

5x8=40 3x8=24 3:6 40-8 =32 thus 3x8 =25 4x8=32 which is 3:4

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vagabundo [1.1K]

Answer:

v = 8

Step-by-step explanation:

-10= -5/4v first multiply both sides of the equation by -4/5

-10(-4/5) = v this cancels out the right side.

multiply the left side.

so you are left with 40/5 = v

next, simplify you will get 8=v

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3 years ago

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Problem 10: A tank initially contains a solution of 10 pounds of salt in 60 gallons of water. Water with 1/2 pound of salt per g

AysviL [449]

Answer:

The quantity of salt at time t is $m_{salt} = (60)\cdot (30 - 29.833\cdot e^{-\frac{t}{10} })$ , where t is measured in minutes.

Step-by-step explanation:

The law of mass conservation for control volume indicates that:

$\dot m_{in} - \dot m_{out} = \left(\frac{dm}{dt} \right)_{CV}$

Where mass flow is the product of salt concentration and water volume flow.

The model of the tank according to the statement is:

$(0.5\,\frac{pd}{gal} )\cdot \left(6\,\frac{gal}{min} \right) - c\cdot \left(6\,\frac{gal}{min} \right) = V\cdot \frac{dc}{dt}$

Where:

$c$ - The salt concentration in the tank, as well at the exit of the tank, measured in $\frac{pd}{gal}$ .

$\frac{dc}{dt}$ - Concentration rate of change in the tank, measured in $\frac{pd}{min}$ .

$V$ - Volume of the tank, measured in gallons.

The following first-order linear non-homogeneous differential equation is found:

$V \cdot \frac{dc}{dt} + 6\cdot c = 3$

$60\cdot \frac{dc}{dt} + 6\cdot c = 3$

$\frac{dc}{dt} + \frac{1}{10}\cdot c = 3$

This equation is solved as follows:

$e^{\frac{t}{10} }\cdot \left(\frac{dc}{dt} +\frac{1}{10} \cdot c \right) = 3 \cdot e^{\frac{t}{10} }$

$\frac{d}{dt}\left(e^{\frac{t}{10}}\cdot c\right) = 3\cdot e^{\frac{t}{10} }$

$e^{\frac{t}{10} }\cdot c = 3 \cdot \int {e^{\frac{t}{10} }} \, dt$

$e^{\frac{t}{10} }\cdot c = 30\cdot e^{\frac{t}{10} } + C$

$c = 30 + C\cdot e^{-\frac{t}{10} }$

The initial concentration in the tank is:

$c_{o} = \frac{10\,pd}{60\,gal}$

$c_{o} = 0.167\,\frac{pd}{gal}$

Now, the integration constant is:

$0.167 = 30 + C$

$C = -29.833$

The solution of the differential equation is:

$c(t) = 30 - 29.833\cdot e^{-\frac{t}{10} }$

Now, the quantity of salt at time t is:

$m_{salt} = V_{tank}\cdot c(t)$

$m_{salt} = (60)\cdot (30 - 29.833\cdot e^{-\frac{t}{10} })$

Where t is measured in minutes.

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3 years ago

A trust fund worth $25,000 is invested in two different portfolios, this year, one portfolio is expected to earn 5.25% interest

OLEGan [10]

Answer:

The amount of money that should be invested at the rate of 5.25% is $12,000 and the amount money that should be invested at the rate of 4% is $13,000

Step-by-step explanation:

we know that

The simple interest formula is equal to

$I=P(rt)$

where

I is the Final Interest Value

P is the Principal amount of money to be invested

r is the rate of interest

t is Number of Time Periods

Let

x ------> the amount of money that should be invested at the rate of 5.25%

25,000-x -----> the amount money that should be invested at the rate of 4%

in this problem we have

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substitute in the formula above

$I=P_1(r_1t)+P_2(r_2t)$

$1,150=x(0.0525*1)+(25,000-x)(0.04*1)$

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$1,150=0.0525x+1,000-0.04x$

$0.0525x-0.04x=1,150-1,000$

$0.0125x=150$

$x=\$12,000$

$|$25,000-x=\$13,000$

therefore

The amount of money that should be invested at the rate of 5.25% is $12,000 and the amount money that should be invested at the rate of 4% is $13,000

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cestrela7 [59]

Answer:

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Step-by-step explanation:

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Perimeter = 2 (10'5" + 6'1")

Perimeter = 2(16'6")

Perimeter = 32'12"

Having in mind our conversion rate of 12 inches equals 1 foot, the results can be properly expressed as 32 feet plus 1 foot which gives us 33 feet.

If the perimeter of Wendy's room is now given as 33 feet, the conversion rate between feet and yards can now be applied. Having been given that

3 feet = 1 yard

Then 1 yard = 3 feet/3, that is

y = 3/3

Hence,

y = 33/3

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3 years ago

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valentinak56 [21]

Answer:

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Step-by-step explanation:

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2a + 6b + c = $18 -----(3)

From equation (1), b = a ÷ 3 ---------(4)

Substitute equations (2) and (4) in equation (3)

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Therefore, 1 Pen cost $2.25

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