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
Firlakuza [10]
4 years ago
14

A man can walk from A to B and back in a certain time at 7 km/hr.If he walks from A to B at 8 km/hr and returns from B to A at 6

km/hr he takes 2 minutes more.Find the distance between A and B.
Mathematics
1 answer:
DerKrebs [107]4 years ago
4 0
We calculate the speed by dividing the distance over time:
s = d/t
So the distance described in the problem is always the same, A to B and B to A.
But we are told that;
7 = d/t
7 = 2d/(t + 2)
that is, the first equation say that at speed 7 km/h a distance d is walked in a time t
the second equation say that at a average speed of 7 (that is 8 on one way and 6 in the other: 8 + 6 = 14, half of it), twice the distance is walked in a time equal to the first time plus 2 minutes.
So we have a system of linear equations, 2 of them with two unknowns, we can solve that:
7 = d/t
7 = 2d/(t + 2<span>)
</span>lets simplify them:
7t = d
7(t + 2) = 2d
7t = 2d - 14
we substitute the first in the second:
<span>7t = 2d - 14
</span><span>7t = d
</span>so:
d = 2d - 14
d = 14
so the distance between A and B is 14 km
You might be interested in
At a local fitness center members pay a a $ 14 membership fee and $ 2 for each aerobics class. Nonmembers pay $ 4 for each aerob
mestny [16]

14+2x=4x: divide 2x on each side

14=2x: divide by 2

7=x

7

8 0
3 years ago
What two numbers can multiply to get -84 but can add up to get -17?
miss Akunina [59]

Answer:

<em>-21 and 4</em>

Step-by-step explanation:

They multiply to a negative number, so you need a positive number and a negative number.


5 0
3 years ago
Read 2 more answers
What is the length of the segment with endpoints (-3, 4) and (5, 4)? A) 2 B) 8 C) 16 D) 64 E) 2 17
Cerrena [4.2K]

Answer:

The correct answer is B) 8

Step-by-step explanation:

\sqrt{(4-4)^{2}+(5+3)^{2}   } \\\\\\\sqrt{8^{2} } \\\\8

8 0
3 years ago
Read 2 more answers
I NEED HELP FAST
deff fn [24]

The restaurant served 70 specials in all, 80% of which were salmon filets. It says to find salmon filets that the restaurant served last night.

So we just need to find 80% of 70.

Therefore, Number of Salmon Filets = 0.8*70 = 56.

Hence, the restaurant served 56 salmon filets.

5 0
3 years ago
9. Rachel wants to draw a triangle with
strojnjashka [21]

I think its 6 cm for the 3rd side

5 0
3 years ago
Other questions:
  • Write each fraction in simplest form 6/9 4/10 15/20 29/24 16/56 45/72 18/60 32/72
    9·2 answers
  • The recycling bin in the shape of a rectangular prism is 15.5 inches long, 8 inches wide and 7 inches high. The recycling bins n
    8·1 answer
  • Paige feeds her dog 0.12 kilograms of dry dog food each day. She wants to buy the smallest bag that has enough food to feed his
    15·2 answers
  • What is the volume of a right circular cylinder with a radius of 3 in. and a height of 10 in.?​
    13·1 answer
  • During a certain six-year
    5·1 answer
  • Sarah is playing a game in which she rolls a number cube 20 times. The results are recorded in the chart below. What is the expe
    9·1 answer
  • 2|3x - 2|= 14 how would you solve this absolute value equation?
    15·2 answers
  • Which of the statements below is true for the following set of numbers?
    15·1 answer
  • Simplify x^2 over x^2 - 2x
    14·1 answer
  • Simplify the expression (show ur work)
    14·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!