If you can get this you’re saving my life

Why is the answer B?

Radda [10]

Remark

Whatever the original price, he gets 70% in the first instance.

He gets 80% in the second instance.

He gets 90% in the third instance

His total income is 240 dollars.

Let the original price be x

Equation

70%x + 80%x +90%x = 240

70% = 0.7 ; 80% = 0.8 ;90% = 0.9

Solution

0.7x + 0.8x + 0.9x = 240 Take out x as a common factor and add the decimals.

x (0.7 + 0.8 + 0.9) = 240

2.4x = 240 Divide both sides by 2.4

x = 240/2.4

x = 100

So the watches should have brought in 3*100 = 300 dollars.

He only brought in 240 dollars.

He lost 300 - 240 = 60 dollars.

The answer is B.

7 0

3 years ago

An automobile manufacturer has given its van a 31.3 miles/gallon (MPG) rating. An independent testing firm has been contracted t

Fynjy0 [20]

Answer:

$z=\frac{31.1-31.3}{\frac{1.3}{\sqrt{140}}}=-1.82$

The p value for this case would be given by:

$p_v =2*P(z$

For this case since the p value is higher than the significance level we have enough evidence to FAIL to reject the null hypothesis and we can conclude that the true mean is not significantly different from 31.3 MPG

Step-by-step explanation:

Information given

$\bar X=31.1$ represent the sample mean

$\sigma=1.3$ represent the population standard deviation

$n=140$ sample size

$\mu_o =31.3$ represent the value that we want to test

$\alpha=0.02$ represent the significance level for the hypothesis test.

z would represent the statistic

$p_v$ represent the p value

Hypothesis to test

We want to test if the true mean is equal to 31.3 MPG, the system of hypothesis would be:

Null hypothesis: $\mu =31.3$

Alternative hypothesis: $\mu \neq 31.3$

Since we know the population deviation, the statistic is given by

$z=\frac{\bar X-\mu_o}{\frac{\sigma}{\sqrt{n}}}$ (1)

Replacing we got:

$z=\frac{31.1-31.3}{\frac{1.3}{\sqrt{140}}}=-1.82$

The p value for this case would be given by:

$p_v =2*P(z$

For this case since the p value is higher than the significance level we have enough evidence to FAIL to reject the null hypothesis and we can conclude that the true mean is not significantly different from 31.3 MPG

4 0

3 years ago

5 (2x + 2) - 22=2 (3x+4)

Natalija [7]

Answer:

x+5

Step-by-step explanation:

If you need the work, let me know!

4 0

2 years ago

"a u.S. 1-cent coin (a penny) has a diameter of 19 mm and a thickness of 1.5 mm". Assume the coin is made of pure copper, whose

choli [55]

the question is Calculate the value of the copper in the coin

Step 1

Find the volume of the coin

we know that

the volume of a cylinder is equal to

$V=\pi r^{2}h$

where

r is the radius of the coin

h is the thickness of the coin

in this problem we have

Diameter=19 mm=1.9 cm

r=D/2------> r=1.9/2=0.95 cm

h=1.5 mm=0.15 cm

substitute the values in the formula

$V=\pi*0.95^{2}*0.15=0.425\ cm^{3}$

Step 2

Find the mass of copper in the coin

we know that

the density is equal to

$Density=mass/volume$

Solve for the mass

$mass=Density*volume$

we have

$Density=8.9\ gr/cm^{3}\\Volume=0.425\ cm^{3}$

substitute in the formula

$mass=8.9*0.425=3.785\ gr$

Step 3

Find the cost

we know that

the market price of the copper is $2.15 per pound

1 pound=453.592 grams

convert gram to pounds

3.785 gr=3.785/453.592=0.0083 pounds

0.0083*$2.15=$0.018=$0.02

therefore

the answer is

$0.02

3 0

3 years ago

There are 2 containers of milk in Eric’s refrigerator. One has 3/5 gallon of milk. The other has 3/4 gallon of milk. How many ga

jeka57 [31]

answer

27/20

Step-by-step explanation:

3/5+3/4

12+15= 27

lcm= 20

6 0

3 years ago