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					 Two trains of lengths 150m and 180m respectively are running in opposite directions on parallel tracks. If their speeds be 50 km/hr and 58 km/hr respectively, in what time will they cross each other?
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                        - 22 seconds
- 15 seconds
- 30 seconds
- 11 seconds
 
Correct Option: D
Relative speed = (50 + 58) kmph
| = |  | 108 × |  | m/sec. | |
| 18 | 
= 30 m/sec
| ∴ Required time = | |
| Relative Speed | 
| = |  |  | seconds | |
| 30 | 
| = |  |  | seconds | |
| 30 | 
= 11 seconds
 
	