Ravi travels 800 km/h partly by train partly by car. He takes 17 hours to travel 600 km by train and rest by car . He takes 12 minute more if he travels 560 km by train and the rest by car . Determine the speed of the car and of the train

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sqdancefan sqdancefan · Answer 1 · 2019-08-10T22:42:51+02:00

Answer:

Step-by-step explanation:

Let t and c represent the speeds of the train and car (in km/h), respectively. The applicable relationship is ...

time = distance/speed

so we have fir the first trip ...

600/t + 200/c = 17

and for the second trip ...

560/t +240/c = 17.2 . . . . . . 17 hours + 12 minutes = 17.2 hours

These equations can be fairly easily solved using Cramer's rule*:

t = (200·560 -240·600)/(200·17.2 -240·17) = -32000/-640 = 50

c = -32000/(17·560 -17.2·600) = -32000/-800 = 40

The speed of the train is 50 km/h; the speed of the car is 40 km/h.

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* Cramer's rule ordinarily gives a ratio for the variables x=1/t and y=1/c. By inverting that ratio, we can find the values of t and c.

The applicable "Cramer's rule" for ...

is ...