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
Nady [450]
3 years ago
13

A skateboarder went a kilometer in 3 minutes with the wind, and returned in four minutes against the wind.

Mathematics
1 answer:
inn [45]3 years ago
8 0

Step-by-step answer:

Answer to problems of this kind is the reciprocal of the harmonic mean of the time required.

We need to find the average of the speeds, not the average of the time.

The respective speeds are 1/3 and 1/4.

The average of the speeds is therefore (1/3+1/4)/2 = 7/24  (harmonic mean of the time taken).

The time required is therefore the reciprocal of the unit speed,

T = 1/(7/24) = 24/7 = 3 3/7 minutes, or approximately 3.43 minutes.

You might be interested in
A parking lot charges $3 to park a car for the first hour and $2 per hour after that. If you use more than one parking space, th
fenix001 [56]
Consider the charge for parking one car for t hours.

If t is more than 1, then the function is y=3+2(t-1), because 3 $ are payed for the first hour, then for t-1 of the left hours, we pay 2 $.

If t is one, then the rule y=3+2(t-1) still calculates the charge of 3 $, because substituting t with one in the formula yields 3.


75% is 75/100 or 0.75. 

For whatever number of hours t, the charge for the first car is 3+2(t-1) $, and whatever that expression is, the price for the second car and third car will be 

0.75 times 3+2(t-1). Thus, the charge for the 3 cars is given by:

3+2(t-1)+0.75[3+2(t-1)]+0.75[3+2(t-1)]=3+2(t-1)+<span>0.75 × 2[3 + 2(t − 1)].


Thus, the function which total parking charge of parking 3 cars for t hours is:

</span><span>f(t) = (3 + 2(t − 1)) + 0.75 × 2(3 + 2(t − 1)) 


Answer: C</span>
4 0
3 years ago
The diameter of a circle endpoints are A(-1, 5) and B(4,-3). Use the midpoint formula to find the coordinates of the center of c
mina [271]

Answer:

centre = (\frac{3}{2}, 1 )

Step-by-step explanation:

using the midpoint formula

midpoint = [\frac{1}{2}(- 1 + 4), \frac{1}{2}(5 - 3) ] = (\frac{3}{2}, 1 )


6 0
3 years ago
Factor the Polynomial completely x^2 + 18
Shtirlitz [24]

x² + 18 = (x - 3√2i)(x + 3√2i)

5 0
3 years ago
If using the method of completing the square to solve the quadratic equation x2 −4x+13=0, which number would have to be added to
stiv31 [10]
X²-4x+(4/2)²-(4/2)²+13=0
x²-4x+4-4+13=0


-4 should be added



Mark brainliest please
7 0
3 years ago
10 Tom a reçu un montant d'argent en héritage.
BARSIC [14]
?????????? Umm what’s that language
5 0
3 years ago
Other questions:
  • What are the Swiss flag measurements
    14·1 answer
  • Please answer this in two minutes
    10·2 answers
  • What is g(x)? <br> o<br> o<br> o<br> o<br> o
    8·2 answers
  • Sally wants to purchase some school supplies. Notebooks cost $3 each and Pens cost $2 each. Sally is not allowed to purchase mor
    10·1 answer
  • The data show prices of light bulbs at a home improvement store, rounded to the nearest dollar. Find the interquartile range (IQ
    11·2 answers
  • Use the figure and follow the directions below.
    8·1 answer
  • ASAP!!!! My grade is a 76 if I get a 10/10 on something what will it bring my grade too?
    12·1 answer
  • A rectangular pool has a sidewalk around it. The pool measures 6 feet by 10 feet and the total area of the pool and sidewalk is
    6·1 answer
  • Can someone help ASAP ill give you good rating
    6·2 answers
  • A mixture contains 3.7 × 10–6 grams of carbon powder and 0.000092 grams of ammonium carbonate.
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!