Question

8. A train covers the first 60, km of its journey at a speed of 80 km/h. the next 90 km at a
speed of 100 km/h, and the rest of its 330-km journey at a speed of 120 km/h. Find the
total time taken to complete its journey. Also, find its average speed
​

Answer 1

Answer:

Step-by-step explanation:

Total time taken by the train during its whole journey

=

\begin{gathered}( \frac{60}{80} + \frac{90}{100} + \frac{330}{120} ) hours \\ = > \frac{900 +1080 + 3300 }{1200} hours \\ = > \frac{5280}{1200} hours \\ = > 4.4hours\end{gathered}

(

80

60

+

100

90

+

120

330

)hours

=>

1200

900+1080+3300

hours

=>

1200

5280

hours

=>4.4hours

Therefore average speed

=

\begin{gathered} \frac{total \: distace}{total \: time} = \frac{(60 + 90 + 330)}{4.4} km.h {}^{ - 1} \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: = > 109.09km.h {}^{ - 1} \end{gathered}

totaltime

totaldistace

=

4.4

(60+90+330)

km.h

−1

=>109.09km.h

−1

Step-by-step explanation:

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