Quantitative Aptitude Topic of the day: Time Speed and Distance
Continuing our daily posts for Quantitative Aptitude, here are today’s concept and questions.
1) Speed , Distance and Time are related in the following way
Speed = Distance / Time
Distance = Speed* Time
2) Average Speed = 2xy / x+y
If an object travels at x km/hr for a certain distance and at y km/hr for the same distance.
The only thing to remember is that average speed is not just an average of two speeds i.e. x+y/2. It is equal to 2xy / x+y
3) All values must be converted to same units .
Conversion of km/ hr to m/ sec and m/ sec to km/ hr
Covert km to m by multiplying by 1000
Convert hr to seconds by multiplying with 60*60 = 3600
So x km/hr = x * 1000/3600 = x * 5/18 m/sec
4) Time is inversely proportional to speed.i.e.e for the same distance if speed increases time taken decreases and vice versa.
Attempt the following questions to check your level of preparedness for ratio proportion questions in competitive exams. You can answer the questions in comments section. Also make sure you checkout tomorrow’s Lunch update for solutions to these questions along with the formulae used in VIDEO format by our Subject Expert.
Question 1 : Two trains of equal lengths take 10 seconds and 15 seconds respectively to cross a telegraph post. If the length of each train be 120 metres, in what time (in seconds) will they cross each other travelling in opposite direction?
Question 2: Two trains running in opposite directions cross a man standing on the platform in 27 seconds and 17 seconds respectively and they cross each other in 23 seconds. The ratio of their speeds is:
Question 3: Two trains, one from Howrah to Patna and the other from Patna to Howrah, start simultaneously. After they meet, the trains reach their reach their destinations after 9 hours and 16 hours respectively. the ratio of their speeds is:
Question 4: A car moves at the speed of 80 km/hr. What is the speed of the car in metres per second?
A) 8 m/sec
B) 20 1/9 m/sec
C) 22 2/9 m/sec
D) 24 m/sec
Question 5: A train covers a distance of 10 km in 12 minutes. If its speed is decreased by 5 km/hr, the time taken by it to cover the same distance will be:
A) 10 min
B) 11 min 20 sec
C) 13 min
D) 13 min 20 sec
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