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Darina [25.2K]
3 years ago
6

A train travels 250 km with a average speed of 75 km/hr and 350 km with 70km/hr and 200 km with average speed of 30km/hr. What w

ill the average speed of whole journey of the train?
Mathematics
1 answer:
pentagon [3]3 years ago
3 0

Answer:

53 1/3 km/h

Step-by-step explanation:

average speed = (total distance)/(total time)

average speed = distance/time

time * average speed = distance

time = distance/(average speed)

250 km at 75 km/h

distance = 250 km

time = (250 km)/(75 km/h) = 3.33333... hours

350 km at 70 km/h

distance = 350 km

time = (350 km)/(70 km/h) = 5 hours

200 km at 30 km/h

distance = 200 km

time = (200 km)/(30 km/h) = 6.6666...  hour

total distance = 250 km + 350 km + 200 km = 800 km

total time = 3.33333... hours + 5 hours + 6.66666... hours = 15 hours

average speed = (total distance)/(total time)

average speed = (800 km)/(15 hours)

average speed = 53 1/3 km/h

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frutty [35]

Answer:

The relationship is proportional for the turtle and the equation is Distance = 54*Time

Step-by-step explanation:

Turtle’s run:

Distance (meters) | Time (minutes)

108                        | 2  

405                       | 7.5

540                       | 10

1768.5                   | 32.75

Rabbitt’s run:

Distance (meters) | Time (minutes)

800                       | 1  

900                       | 5

1107.5                    | 20

1524                      | 32.5

The relationship between distance traveled and time is proportional if this equation is satisfied:  

Distance = k*Time or k = Distance/Time

where k is a constant

For the turtle:

108/2 = 405/7.5 = 540/10 = 1768.5/32.75 = 54

Then, the relationship is proportional and the equation is Distance = 54*Time

For the rabbit:

800/ 1 = 800  

900/5 = 180

1107.5/20  = 55.375

1524/32.5  = 46.89

Then, the relationship is not proportional.

7 0
3 years ago
2)
ycow [4]

Answer:

The altitude is changing at a speed of 200 √3 km/hr

Step-by-step explanation:

Here, we want to know how far the altitude of the plane is changing

we are told that the airplane makes an angle of 60 degrees with the ground

So therefore , the rate of change of its altitude will be ;

sin 60 = x/ 400

x = 400 sin 60

x = 400 * √3/2

x = 200 √3 km/hr

4 0
3 years ago
PROBIBILITY HELP ME PLZ Mike is playing a game where a ball is hidden under one of 5 cups. Mike guesses which cup contains the b
SVETLANKA909090 [29]

Answer:

Choose 1 ball from a bag with 1 red ball and 4 white balls. Record the color, replace the ball and repeat the experiment 20 times.

Step-by-step explanation:

Given

Cups = 5

Ball=1

Trials = 20

See attachment

Required

Simulate the above experiment (fill in the gaps)

The probability of choosing a ball correctly in each trial are independent, and each probability is calculated as:

P(Correct) = \frac{Ball}{Cups}

This gives:

P(Correct) = \frac{1}{5}

The number of times (i.e. 6) he chose correctly is not a factor in his simulation

So, a correct simulation of the experiment is as follows:

Choose 1 ball from a bag with 1 red ball and 4 white balls. Record the color, replace the ball and repeat the experiment 20 times.

The selected ball represents the number of balls hidden (i.e. 1 ball).

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7 0
3 years ago
Please help!! Algebra!!
Ivanshal [37]
<h3>Answer:  6x - 3</h3>

Work Shown:

y = expression for the missing side

perimeter = 9x - 1

side1+side2+side3 = perimeter

(2x+4) + (x-2) + (y) = 9x - 1

3x+2 +y = 9x-1

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6 0
3 years ago
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I am Lyosha [343]

Answer:

y^2+x^2=25

Step-by-step explanation:

The formula for the equation of a circle is (y-(y coordinate of circle))^2 + (x-(x coordinate of circle))^2=radius^2. Sorry if this is unclear, PM me if you need more explanation!

3 0
3 years ago
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