Aptitude - Time and Distance - Discussion
Discussion Forum : Time and Distance - General Questions (Q.No. 10)
10.
A car travelling with 
of its actual speed covers 42 km in 1 hr 40 min 48 sec. Find the actual speed of the car.
of its actual speed covers 42 km in 1 hr 40 min 48 sec. Find the actual speed of the car.
Answer: Option
Explanation:
| Time taken = 1 hr 40 min 48 sec = 1 hr 40 | 4 | min = 1 | 51 | hrs = | 126 | hrs. |
| 5 | 75 | 75 |
Let the actual speed be x km/hr.
| Then, | 5 | x x | 126 | = 42 |
| 7 | 75 |
 x = |
 |
42 x 7 x 75 |  |
= 35 km/hr. |
| 5 x 126 |
Discussion:
117 comments Page 7 of 12.
Divya said:
9 years ago
Can anyone please say answer that how to convert the hour to min and hour to sec?
Please anyone tell me the answer.
Please anyone tell me the answer.
ROhit said:
9 years ago
@ Divya.
1hr = 60min
1min = 60 sec
Then 60min = 60 * 60 sec.
Thus 1 hr = 60 * 60 sec = 3600 sec.
Hope it helps.
1hr = 60min
1min = 60 sec
Then 60min = 60 * 60 sec.
Thus 1 hr = 60 * 60 sec = 3600 sec.
Hope it helps.
Sameen said:
9 years ago
@Abhishek.
Why you have written 4/5 as 8/10?
Why you have written 4/5 as 8/10?
Ganesh said:
9 years ago
Actual distance covered by car is 42 km in 1 hr 40 min 48 sec = 100.8 minutes. Now just divide total km by total minutes took = 42/100.8 = 0.416667 km per minute.
Then per hr speed = 0.416667 km per minute * 60 minutes = 25 kmph as the car was running @ 5/7 of it's actual speed.
Then 5 = 25 and 7 = ?
The answer is 25/5 = 5.
5 * 7 = 35 kmph.
Then per hr speed = 0.416667 km per minute * 60 minutes = 25 kmph as the car was running @ 5/7 of it's actual speed.
Then 5 = 25 and 7 = ?
The answer is 25/5 = 5.
5 * 7 = 35 kmph.
Avi goyal said:
9 years ago
Time = 1 hr 40 min 48 sec.
= 1hr + 40/60hr + 48/3600 hr = 1 + 2/3 + 1/75 = 126/75 hr.
Distance = 42 km.
Speed = distance/time = 42/(126/75) = 42 * 75/126.
5/7 of the actual speed = 42 * 75/126.
Actual speed = 42 * 75/126 * 7/5.
= 42 * 15/18.
= 7 * 15/3.
= 7 * 5 = 35 km/hr.
= 1hr + 40/60hr + 48/3600 hr = 1 + 2/3 + 1/75 = 126/75 hr.
Distance = 42 km.
Speed = distance/time = 42/(126/75) = 42 * 75/126.
5/7 of the actual speed = 42 * 75/126.
Actual speed = 42 * 75/126 * 7/5.
= 42 * 15/18.
= 7 * 15/3.
= 7 * 5 = 35 km/hr.
Suraj said:
9 years ago
Sir, how to change any fraction in time?
Like
7/5 = _ hour, _min?
Like
7/5 = _ hour, _min?
Sandeep Ippakayala said:
8 years ago
5/7u=42/1+2/3+1/75,
5/7u=42/126/75,
5/7u=42*75/126,
5/7u=3150/126,
5*126u=3150 * 7,
630u=22050,
u = 35KM.
Time in Hours:
1*75/75+2*25/3*25+1/75.
75+50+1/75.
126/75.
1hr=60min.
1/60hr=1min.
1min=60sec.
1/60min=1sec.
5/7u=42/126/75,
5/7u=42*75/126,
5/7u=3150/126,
5*126u=3150 * 7,
630u=22050,
u = 35KM.
Time in Hours:
1*75/75+2*25/3*25+1/75.
75+50+1/75.
126/75.
1hr=60min.
1/60hr=1min.
1min=60sec.
1/60min=1sec.
Amit said:
8 years ago
1hr 40min 48sec.
1hr 40min 48/60 ---to convert sec to min.
1hr 40min 4/5.
1hr 40/60 4/5 ---to convert min to hr.
1hr 51/75.
1hr 40min 48/60 ---to convert sec to min.
1hr 40min 4/5.
1hr 40/60 4/5 ---to convert min to hr.
1hr 51/75.
Hareesh said:
8 years ago
Thanks @Siddharth.
Kazi faruque said:
8 years ago
Thanks @Siddharth.
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