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Train P travels for 330 km at an average speed of x km/h from Kuala Lumpur to Kota Bahru. Train Q travels from Kota Bahru at an average speed of (x-5) km/h and arrives at Kuala Lumpur 30 minutes earlier than train P. Calculate the total time, in hours taken by the 2 trains. ​

Respuesta :

Answer:

Train P : [tex]t_{P} =\frac{330}{55}=6\ \text{hours}[/tex]

Train Q : [tex]t_{Q} =\frac{330}{55}+\frac{1}{2}=6\ \text{hours}\ 30\ \text{minutes}[/tex]

Step-by-step explanation:

The formula to compute the distance traveled by a train is:

[tex]d=s\times t[/tex]

Here,

d = distance traveled

s = speed of the train

t = time taken

From the provided information:

Train P :

d = 330 km

s = x km/h

Then time taken is:

[tex]t=\frac{d}{s}=\frac{330}{x}[/tex]

Train Q :

d = 330 km

s = (x - 5) km/h

[tex]t=\frac{330}{x}+\frac{1}{2}[/tex]

Both the trains traveled the same distance.

[tex]x\times \frac{330}{x}=(x-5)\times [\frac{330}{x}+\frac{1}{2}]\\\\330=\frac{330(x-5)}{x}+\frac{x-5}{2}\\\\330\times 2x=[660(x-5)+x(x-5)]\\\\660x=660x-3300+x^{2}-5x\\\\x^{2}-5x-3300=0\\\\x^{2}+60x-55x-3300=0\\\\x(x+60)-55(x+60)=0\\\\(x-55)(x+60)=0\\\\x=55[/tex]

Compute the time taken by the two trains as follows:

Train P : [tex]t_{P} =\frac{330}{55}=6\ \text{hours}[/tex]

Train Q : [tex]t_{Q} =\frac{330}{55}+\frac{1}{2}=6\ \text{hours}\ 30\ \text{minutes}[/tex]