1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
GalinKa [24]
3 years ago
10

Starting at home, Luis traveled uphill to the gift store for 50 minutes at just 6 mph. He then traveled back home along the same

path downhill at a speed of 12 mph.
What is his average speed for the entire trip from home to the gift store and back?
Mathematics
1 answer:
Orlov [11]3 years ago
8 0

Let S = his average speed.

Let D = distance traveled one way

Time = distance / speed

Set up an equation:

d/6 + d/12 = 2d/S

Multiply the equation by 12s:

12s(d/6) + 12s(d/12) = 12s(2d/s)

Simplify to get:

2sd + sd = 24d

Combine like terms:

3sd = 24d

Divide both sides by d:

3s = 24

Divide both sides by 3:

s = 24/3

s = 8

His average speed was 8 mph.

You might be interested in
A sociologist develops a test to measure attitudes towards public transportation, and 27 randomly selected subjects are given th
taurus [48]

Answer:

The margin of error for the 95% confidence interval for the mean score of all such subjects is of 8.45.

Step-by-step explanation:

We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.

The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So

df = 27 - 1 = 26

95% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 26 degrees of freedom(y-axis) and a confidence level of 1 - \frac{1 - 0.95}{2} = 0.975. So we have T = 2.0518

The margin of error is:

M = T\frac{s}{\sqrt{n}}

In which s is the standard deviation of the sample and n is the size of the sample.

In this question:

n = 27, s = 21.4. So

M = 2.0518\frac{21.4}{\sqrt{27}}

M = 8.45

The margin of error for the 95% confidence interval for the mean score of all such subjects is of 8.45.

5 0
3 years ago
Find 4 irrational number between 0.1 and 1.12​
Lelu [443]

I'm sorry but I do not know how to do this

5 0
3 years ago
Evan, Claire, Jaya and Tim are running a 3km relay race.
Kruka [31]

Answer:

Tim needs to finish 59/90

Step-by-step explanation:

Add together what Evan Claire and Jaya ran  

9/10 + 7/9+ 2/3

The common denominator is 90

9/10 (9/9) +7/9 *10/10  + 2/3 *30/30

81/90 + 70/90 + 60/90

211/90

We need 3 km = 3 *90/90 = 270 /90

270/90 - 211/90 = 59/90

5 0
3 years ago
A commercial property purchased for 1.2 million is revalued at 995,000. Calculate the percentage decrease in the property’s valu
soldi70 [24.7K]

Answer:

17%

Step-by-step explanation:

First: work out the difference (decrease) between the two numbers you are comparing. Then: divide the decrease by the original number and multiply the answer by 100.

First:

1,200,000 - 995,000 = 205,000

Then:

205,000 / 1,200,000 = 0.17

0.17 × 100% = 17%

4 0
3 years ago
Read 2 more answers
Please help I only have an hour. ​
Goshia [24]

Answer:

Slope (m) = \frac{y}{x} = \frac{2}{3} = 0.66666666666667

Step-by-step explanation:

0 = arctan (\frac{y}{x}) = 33.69006752598°

X = 4 – 1 = 3

Y = 4 – 2 = 2

Distance (d) = \sqrt{x^2+y^2}= \sqrt{13} =3.605551275464

Equation of the line:

y = 0.66666666666667x + 1.3333333333333

or

y=\frac{2}{3}x+\frac{4}{3}

When x=0, y = 1.3333333333333

When y=0, x = -2

4 0
2 years ago
Other questions:
  • PLSSSSSSSS HELP (2 + 7i) - (6 + 8i) + (10 - 10i)
    5·1 answer
  • What is the value of the expression when a is 5 and b is 3 4a^2-5b^2
    10·1 answer
  • Solve this equation (2.2)(4.5)(0.6)
    6·1 answer
  • Escribir 1/4 como in percentage​
    13·1 answer
  • NEED SOME HELPP PLEASE
    6·1 answer
  • If x+3y upon 5x+4y= 1/3 find the ratio of x:y ANSWER FASTTT
    15·2 answers
  • Write the equation of the line that passes through the points (-5, 2) and<br> (0, -1)
    12·1 answer
  • Sobre un cuerpo se aplica una fuerza de 30 N y se desplaza 8 metros; el trabajo necesario es equivalente a
    6·1 answer
  • A survey concluded that 5 out of every 6 teachers
    12·1 answer
  • Value of the digit 3 for 263 is​
    13·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!