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
s2008m [1.1K]
3 years ago
9

Bill drove to town hall and back. The trip there took 1.5 hours and 2hrs on trip back. If bill's speed there was 12 mph faster t

han on the way back , find his average speed on the way back.
Mathematics
2 answers:
kogti [31]3 years ago
4 0

Answer:

 36 mph

Step-by-step explanation:

Let s represent the speed on the way back. Time is inversely proportional to speed, so the speed ratios are ...

  (speed going)/(speed coming) = (s+12)/s = 2/1.5 = (time coming back)/(time going there)

  1 +(12/s) = 4/3 . . . . . divide, simplify the ratio

  12/s = 1/3 . . . . . . .  subtract 1

  s = 36 . . . . . . . . .  multiply by 3s

Bill's average speed on the way back was 36 mph.

_____

I sometimes like to think of these problems in terms of "ratio units." We have the speed ratio:

  (s+12)/s = 2/1.5 = 4/3

The difference between s+12 and s is 12 mph, and that corresponds to the difference 4-3 = 1 ratio unit. So 3 ratio units will be 36 mph, corresponding to the value of s. Bill's speed on the way back was 36 mph.

  (48 mph)/(36 mph) = 4/3 . . . . <em>check</em>

kipiarov [429]3 years ago
3 0

Answer:

36 mph.

Step-by-step explanation:

Let x be the distance to the town hall.

Trip there:

speed (s) = distance / time

s = x / 1.5 so x = 1-5s

Trip back:

s - 12 = x / 2 so x = 2s - 24

AS they are both = to x:

1.5s = 2s - 24

0.5s = 24

s = 48.

Average speed on the way back = 48-12 = 36 mph.

You might be interested in
A scuba diver dove 18 ft below the
Vlada [557]

Answer:

42 ft

Step-by-step explanation:

18 plus 24 equals 42 feet

6 0
3 years ago
Read 2 more answers
1)In a sample of 100 households, the mean number of hours spent on social networking sites during the month of January was 50 ho
ra1l [238]
So the following is the answer of the following question in your problem and please do not post to many question in just one posting. 
#1 The 98% confidence interval for the mean hours is between 6 and 50.
#2 The smallest margin of error between the two is southern florida with 1.8% margin of error.
8 0
3 years ago
Y=4x+8 y=-x-7 solve by substitution
nikklg [1K]

Step-by-step explanation:

Alrighty! here you go image.

7 0
3 years ago
Read 2 more answers
Find tan(450-a), If <br><img src="https://tex.z-dn.net/?f=%20%5Ctan%28a%29%20%3D%20%20%5Cfrac%7B1%7D%7B2%7D%20" id="TexFormula1"
Inessa05 [86]

Answer:

tan(450-a)=5\sqrt{3}-8

Step-by-step explanation:

We know that:

tan(a-b)=\frac{tan(a)-tan(b)}{1+tan(a)tan(b)}

tan(450-a)=\frac{tan(450)-tan(a)}{1+tan(450)tan(a)}

Remember:

450°=360°+60°

and:

tan(a)=\frac{1}{2}

Thus:

tan(450-a)=\frac{tan(60)-tan(a)}{1+tan(60)tan(a)}\\\\

Then:

tan(450-a)=5\sqrt{3}-8

4 0
2 years ago
Danielle has $3 in quarters and $2 in dimes in her pocket. If she randomly selects one coin out of her
sattari [20]
The answer is C. 3/5
6 0
3 years ago
Other questions:
  • What is the slope of a line with these coordinate points&gt;<br><br> (-5,-4) (5,1)
    6·2 answers
  • What is the answer too 509+35+12
    12·2 answers
  • Multiplication facts
    14·1 answer
  • What is 1/2 changed to a mixed number
    7·2 answers
  • 7 was multiplied by a particular number. This product was added to 12, then divided by 10. The resulting quotient was -3. Give t
    14·1 answer
  • Find the surface area of this rectangle prism L=6 H=6 W=4​
    12·1 answer
  • The equation of the line is​
    7·1 answer
  • HELLLLLLLLLLLLLLLLLLLLLLLLLLP
    8·1 answer
  • Pls help me pls I’ll give brainliest for right answer!
    8·1 answer
  • F I sold 3 coffees for $2.50 each, how much change do I give the customer from the following amounts?
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!