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
Anuta_ua [19.1K]
3 years ago
9

On a certain trip, a motorist drove 6 miles at 20mph, 6 miles at 30mph, and 6 miles at 40mph. What portion of the total driving

time did she spend driving 30mph?
Mathematics
1 answer:
NikAS [45]3 years ago
7 0

Answer:

  4/13

Step-by-step explanation:

Driving time is ...

  time = distance/speed

Then the ratio of times is ...

  6/20 : 6/30 : 6/40

  = 3/10 : 1/5 : 3/20

If we multiply by 20, we can get integer ratios:

  = 6 : 4 : 3

The middle ratio number represents the time spent at 30 mph, and the total of all ratio numbers represents the total driving time. Then the fraction spent at 30 mph is ...

  4/(6+4+3) = 4/13

_____

Total driving time was 13/20 hours, or 39 minutes. Of that time, 12 minutes was spent driving at 30 mph.

You might be interested in
What is the equation in point−slope form of the line passing through (0, 6) and (1, 3)? (5 points)
Andrews [41]

The slope-point formula:

y-y_1=m(x-x_1)

m=\dfrac{y_2-y_1}{x_2-x_1}

We have (0, 6) and (1, 3),

Substitute:

m=\dfrac{3-6}{1-0}=\dfrac{-3}{1}=-3\\\\y-6=-3(x-0)

6 0
3 years ago
I picked the second one, was I correct?
Assoli18 [71]

Answer:

yes

Step-by-step explanation:

3 0
3 years ago
Read 2 more answers
The ratio of boys to girls in a class is 2:3. there are twelve boys in the class. how many girls are there
gogolik [260]
The answer is 18

Solution: 2:3 2x6=12
3x6=18
Hope this help
4 0
3 years ago
Number 15. Find the equation of the line that passes through (3,-1) and is perpendicular to the line that passes through (-5, 2)
MArishka [77]
For lines to be perpendicular their slopes must be negative reciprocals of one another, mathematically:

m1*m2=-1

So we first need to find the slope of the reference line.

m=(y2-y1)/(x2-x1)=(7-2)/(-1--5)=5/4

So the perpendicular line will have a slope of:

5m/4=-1

m=-4/5

So our perpendicular line so far is:

y=-4x/5+b, now we can use point (3,-1) to solve for the y-intercept, "b"

-1=-4(3)/5+b

-1=-12/5+b

-5/5+12/5=b

7/5=b

So the line is:

y=-4x/5+7/5 or more neatly

y=(-4x+7)/5

y=-0.8x+1.4
3 0
3 years ago
Find m∠X. Put the answer below.<br> m∠X =
Vika [28.1K]

Answer: 30 deg

Step-by-step explanation:

This is an example of a 30-60-90 triangle because the proportions of the sides are 1-2-sqrt(3). Therefore m<X = 30 degrees.

3 0
2 years ago
Other questions:
  • <img src="https://tex.z-dn.net/?f=%20%5Clim_%7Bx%20%5Cto%20%5Cinfty%7D%20%20%5Cfrac%7Bx%2Bcosx%7D%7Bx%7D%20" id="TexFormula1" ti
    9·1 answer
  • What was the average cost of a basic adult funeral in 2010?
    9·1 answer
  • How do you solve 2/3 x=12 one step
    10·1 answer
  • The following data shows the weight in pounds of six bags what is the value of the mean absolute deviation of the weights of the
    5·1 answer
  • HELP ASAP PLEASE ! Questions are in the pic
    10·2 answers
  • 12 points!! Please help out if you can! Means so much!!
    8·1 answer
  • 4d + 7 = 13 <br> Is this an equation or an expression?
    5·1 answer
  • – 2(2x 8) + 4 = 3(x + 4)
    6·1 answer
  • Can someone help please
    12·1 answer
  • Please help with this
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!