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It takes eight hours for a 600 km journey, if 120 km is done by train and the rest by car. It takes 20 minutes more, if 200 km is done by train and the rest by car. The ratio of the speed of the train to that of the car is :
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- 3 : 5
- 3 : 4
- 4 : 3
- 4 : 5
Correct Option: B
Let the speed of train be x kmph. and the speed of car be y kmph.
| Time = | |
| Speed |
According to the question,
| + | = 8 | ||
| x | y |
| ⇒ | + | = 1 .....(i) | ||
| x | y |
| and, | + | = | |||
| x | y | 3 |
| ⇒ | + | = | |||
| x | y | 3 |
| ⇒ | + | = 1 .....(ii) | ||
| x | y |
From equations (i) and (ii),
| ⇒ | + | = | + | ||||
| x | y | x | y |
| ⇒ | − | = | − | ||||
| x | x | y | y |
| ⇒ | = | ||
| x | y |
| ⇒ | = | = | = 3 : 4 | |||
| y | 12 | 4 |
