Ask question

Ask question

All categories

3 years ago

9

A manufacturer of pickup trucks is required to recall all the trucks manufactured in a given year for the repair of possible def

ects in the steering column and defects in the brake linings. Dealers have been notified that 3% of the trucks have defective steering, and that 5% of the trucks have defective brake linings. If 94% of the trucks have neither defect, what percentage of the trucks have both defects

1 answer:

Crank3 years ago

8 0

Answer: 2%

Step-by-step explanation:

Let A be the event of having defective steering and B be the vent of having defective brake linings.

Given: P(A) = 0.03 P(B) = 0.05

P(neither A nor B ) = 0.94

Using formula: P(either A nor B) = 1- P(neither A nor B )

= 1-0.94

i.e. P(either A nor B) =0.06

Using formula:P(A and B) = P(A)+P(B)-P(either A or B)

P(A and B) =0.03+0.05-0.06

= 0.02

Hence, the percentage of the trucks have both defects = 2%

You might be interested in

Find both unit rates.

Alexus [3.1K]

$27 / 4 = 6.75 dollars per hour

4 / 24 = 0.148 = 0.15 hours per dollar

Answer is A

3 0

2 years ago

A tank with a capacity of 500 gal originally contains 200 gal of water with 100 lb of salt in the solution. Water containing1 lb

devlian [24]

Answer:

(a) The amount of salt in the tank at any time prior to the instant when the solution begins to overflow is $\left(1-\frac{4000000}{\left(200+t\right)^3}\right)\left(200+t\right)$ .

(b) The concentration (in lbs per gallon) when it is at the point of overflowing is $\frac{121}{125}\:\frac{lb}{gal}$ .

(c) The theoretical limiting concentration if the tank has infinite capacity is $1\:\frac{lb}{gal}$ .

Step-by-step explanation:

This is a mixing problem. In these problems we will start with a substance that is dissolved in a liquid. Liquid will be entering and leaving a holding tank. The liquid entering the tank may or may not contain more of the substance dissolved in it. Liquid leaving the tank will of course contain the substance dissolved in it. If <em>Q(t)</em> gives the amount of the substance dissolved in the liquid in the tank at any time t we want to develop a differential equation that, when solved, will give us an expression for <em>Q(t)</em>.

The main equation that we’ll be using to model this situation is:

Rate of change of <em>Q(t)</em> = Rate at which <em>Q(t)</em> enters the tank – Rate at which <em>Q(t)</em> exits the tank

where,

Rate at which <em>Q(t)</em> enters the tank = (flow rate of liquid entering) x (concentration of substance in liquid entering)

Rate at which <em>Q(t)</em> exits the tank = (flow rate of liquid exiting) x (concentration of substance in liquid exiting)

Let $C$ be the concentration of salt water solution in the tank (in $\frac{lb}{gal}$ ) and $t$ the time (in minutes).

Since the solution being pumped in has concentration $1 \:\frac{lb}{gal}$ and it is being pumped in at a rate of $3 \:\frac{gal}{min}$ , this tells us that the rate of the salt entering the tank is

$1 \:\frac{lb}{gal} \cdot 3 \:\frac{gal}{min}=3\:\frac{lb}{min}$

But this describes the amount of salt entering the system. We need the concentration. To get this, we need to divide the amount of salt entering the tank by the volume of water already in the tank.

$V(t)$ is the volume of brine in the tank at time t. To find it we know that at t = 0 there were 200 gallons, 3 gallons are added and 2 are drained, and the net increase is 1 gallons per second. So,

$V(t)=200+t$

Therefore,

The rate at which $C(t)$ enters the tank is

$\frac{3}{200+t}$

The rate of the amount of salt leaving the tank is

$C\:\frac{lb}{gal} \cdot 2 \:\frac{gal}{min}+C\:\frac{lb}{gal} \cdot 1\:\frac{gal}{min}=3C\:\frac{lb}{min}$

and the rate at which $C(t)$ exits the tank is

$\frac{3C}{200+t}$

Plugging this information in the main equation, our differential equation model is:

$\frac{dC}{dt} =\frac{3}{200+t}-\frac{3C}{200+t}$

Since we are told that the tank starts out with 200 gal of solution, containing 100 lb of salt, the initial concentration is

$\frac{100 \:lb}{200 \:gal} =0.5\frac{\:lb}{\:gal}$

Next, we solve the initial value problem

$\frac{dC}{dt} =\frac{3-3C}{200+t}, \quad C(0)=\frac{1}{2}$

$\frac{dC}{dt} =\frac{3-3C}{200+t}\\\\\frac{dC}{3-3C} =\frac{dt}{200+t} \\\\\int \frac{dC}{3-3C} =\int\frac{dt}{200+t} \\\\-\frac{1}{3}\ln \left|3-3C\right|=\ln \left|200+t\right|+D\\\\$

We solve for C(t)

$C(t)=1+D(200+t)^{-3}$

D is the constant of integration, to find it we use the initial condition $C(0)=\frac{1}{2}$

$C(0)=1+D(200+0)^{-3}\\\frac{1}{2} =1+D(200+0)^{-3}\\D=-4000000$

So the concentration of the solution in the tank at any time t (before the tank overflows) is

$C(t)=1-4000000(200+t)^{-3}$

(a) The amount of salt in the tank at any time prior to the instant when the solution begins to overflow is just the concentration of the solution times its volume

$(1-4000000(200+t)^{-3})(200+t)\\\left(1-\frac{4000000}{\left(200+t\right)^3}\right)\left(200+t\right)$

(b) Since the tank can hold 500 gallons, it will begin to overflow when the volume is exactly 500 gal. We noticed before that the volume of the solution at time t is $V(t)=200+t$ . Solving the equation

$200+t=500\\t=300$

tells us that the tank will begin to overflow at 300 minutes. Thus the concentration at that time is

$C(300)=1-4000000(200+300)^{-3}\\\\C(300)= \frac{121}{125}\:\frac{lb}{gal}$

(c) If the tank had infinite capacity the concentration would then converge to,

$\lim_{t \to \infty} C(t)= \lim_{t \to \infty} 1-4000000\left(200+t\right)^{-3}\\\\\lim _{t\to \infty \:}\left(1\right)-\lim _{t\to \infty \:}\left(4000000\left(200+t\right)^{-3}\right)\\\\1-0\\\\1$

The theoretical limiting concentration if the tank has infinite capacity is $1\:\frac{lb}{gal}$

4 0

3 years ago

A hot air balloon went from an elevation of 4,064 feet to an elevation of 3,322 feet in 28 minutes. What

ELEN [110]

Answer:

<em>The air balloon descends 26.5 feet per minute</em>

Step-by-step explanation:

<u>Rate of Change</u>

The rate of change is a measure that compares two quantities, usually to know how one variable changes in time.

The hot air balloon was 4,064 feet high and, 28 minutes later, it went to 3,322 feet. We can calculate the rate of descent R by dividing the change of elevation over time:

$\displaystyle R=\frac{3,322-4,064}{28}=\frac{-742}{28}=-26.5$

Thus the air balloon descends 26.5 feet per minute

3 0

3 years ago

Mr.Changs class has 28 students 4/7 of whom are girls. Which equation shows how to determine the number of girls in Mr. Chang’s

irinina [24]

I think 7 of them are girls and the rest are boys and how i got this answer is I took the 28 and divided it by 4 and got 7.

8 0

2 years ago

19 points please hurry

Readme [11.4K]

Answer:

i think the answer is b give me brainliest please

Step-by-step explanation:

5 0

3 years ago