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
olganol [36]
3 years ago
6

Dirk can clean a playground in 5 hours. Geralyn can clean a playground in only 4 hours. Which of the following can be used to de

termine the amount of time it would take for Dirk and Geralyn to clean a playground together?
Mathematics
1 answer:
denis23 [38]3 years ago
7 0
It would take 1hr because if you subtract the hrs
You might be interested in
The speed of the current is 7 mph. The boat travels three times slower against the current than with the current. What is the sp
svlad2 [7]
Let
x--------> <span>the speed of the boat in mph

we know that
</span>going upstream the speed is x-7 
<span>going downstream the speed is x+7 
</span>
let the distance be d 
<span>time to go upstream = d/(x-7) </span>
<span>time to go downstream = d/(x+7)
</span>
time going upstream is 3 times going downstream 
so
<span>3d/(x+7) = d/(x-7) </span>
<span>divide by d </span>
<span>3/(x+7) = 1/(x-7) </span>
<span>3x-21 = x+7 </span>
<span>2x = 28 </span>
<span>x = 14 
</span>
the answer is
<span>the speed of the boat in still water is 14 mph</span>
7 0
3 years ago
How would you find the scale factor in a dilation?
elixir [45]
Starting with ΔABC, draw the dilation image of the triangle with a center at the origin and a scale factor of two. Notice that every coordinate of the original triangle has been multiplied by the scale factor (x2). Dilation with scale factor 2, multiply by 2.
7 0
3 years ago
How many significant figures does each measurement have? 52,000,000 km = significant figures
aleksklad [387]

Answer:

I think the answer is only 2, hope this helps

Step-by-step explanation:

8 0
3 years ago
26. Students who take a statistics course are given a pre-test on the concepts and skills for the first chapter of a statistics
hjlf

The test statistic value lies to the right of the critical value. So we have sufficient evidence to reject the null hypothesis.

<h3>What are null hypotheses and alternative hypotheses?</h3>

In null hypotheses, there is no relationship between the two phenomenons under the assumption or it is not associated with the group. And in alternative hypotheses, there is a relationship between the two chosen unknowns.

Students who take a statistics course are given a pre-test on the concepts and skills for the first chapter of a statistics course.

Then they are given a post-test once the professor has concluded lecturing on the material.

Pre-test and post-test scores for 4 students in an elementary statistics class are given below.

Then we have

\mu _d = \mu _{post} - \mu _{pre}

Then the null hypotheses and alternative hypotheses will be

H₀: \mu _d = 0

Hₐ: \mu _d > 0

Then the test statistic will be

\rm \overline{x} _d = \dfrac{\Sigma x_d}{n} = \dfrac{15+12+10+1}{4}\\\\\overline{x} _d = 9.5

Then

\rm S_d = 6.02

The test statistic value is given by

\rm t = \dfrac{\overline{x} _d }{\dfrac{S_d}{\sqrtn}} \\\\t = \dfrac{9.5}{\dfrac{6.02}{\sqrt4}}\\\\t = 3.16

Since this is a right-tailed test, so the critical value is given by

\rm t_{n-1}(\alpha ) = t_3 (0.05) = 2.353

Since the test statistic value lies to the right of the critical value. So we have sufficient evidence to reject the null hypothesis.

Hence, we can conclude that \mu _d > 0 that is test scores have improved.

More about the null hypotheses and alternative hypotheses link is given below.

brainly.com/question/9504281

#SPJ1

7 0
2 years ago
Please................ . . . .
Alex73 [517]
First, let's solve the inequality
2.9 (x+8) < 26.1
2.9x + 23.2 <26.1
2.9x < 26.1 -23.2
2.9x <2.9
dividing both sides by 2.9 we get:
x < 1
so, it is the last numberline graph, because it contains an empty circle at 1 on the numberline, which means it doesn't include 1. but all numbers less than 1
6 0
3 years ago
Other questions:
  • Find the area of the smaller sector.<br> Round to the nearest tenth.
    12·1 answer
  • What classes do you take in the 11th grade year ?
    6·1 answer
  • In the triangle below, the sec X is x/z
    15·2 answers
  • Which of the combined rectangles has an area of 40 square​
    14·1 answer
  • What is the simple interest that is missing from the table? p $375 r 2.2% t 3 years
    9·2 answers
  • The average home price in a certain area was $272,000 in 2010. In 2020, the average home price was $299,000. What is the rate of
    13·1 answer
  • WILL MARK BRAINLIST!!!!!
    7·2 answers
  • Please answer and show all work !!
    14·1 answer
  • HELP ME FIND THE Y-INTERCEPT
    5·1 answer
  • Multiply 531.7 and 9 together. <br> Round to the nearest hundredth when necessary. <br> Answer:
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!