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 5 of 12.
Tarun said:
1 decade ago
Time taken = 1 hr 40 min 48 sec = 1 hr 40 4/5 min.
= 126/75 hrs.
Actual speed X kmph.
Then Xx126/75 = 42.X = 25 kmph.
35 is incorrect.
= 126/75 hrs.
Actual speed X kmph.
Then Xx126/75 = 42.X = 25 kmph.
35 is incorrect.
Tarun said:
1 decade ago
If a car travelling with 5/7 of its actual speed. Then 35 kmph is possible?
Dheepak ts said:
1 decade ago
Easy method to convert timings:
First convert everything into seconds.
1 hour 40 mins 48 secs.
= 60*60+40*60+48 secs = 3600+2400+48 secs
= 6048 secs.
Now convert secs to hour by dividing it by 60*60 i.e. 3600.
6048/3600 = 42/25 hours you will get.
Apply it in D = S*T.
First convert everything into seconds.
1 hour 40 mins 48 secs.
= 60*60+40*60+48 secs = 3600+2400+48 secs
= 6048 secs.
Now convert secs to hour by dividing it by 60*60 i.e. 3600.
6048/3600 = 42/25 hours you will get.
Apply it in D = S*T.
Komal said:
10 years ago
If a car travelling with a 25 kmph speed which is equal to its 5/7th actual speed then its original/actual speed is 35 kmph.
i.e 5/7 --> 25 i.e
x.1 = 25*7/5.
=> x = 35 kmph.
i.e 5/7 --> 25 i.e
x.1 = 25*7/5.
=> x = 35 kmph.
Rani said:
10 years ago
How we got 42 as distance?
Ruchir said:
10 years ago
I am not able to understand the conversion please explain me.
Vikram said:
10 years ago
Hai @Ruchir.
Given time is: 1 hr 40 min 48 sec.
Conver hr to sec.
First convert hr to min : 1 hr = 60 min.
Next convert min to sec : 60 min = 3600 sec (1 min = 60 sec).
Finally 1 hr = 3600 sec.
Convert min to sec.
40 min = 40*60 sec = 2400 sec.
Then add 3600+2400+48 = 6048 sec.
1 hr 40 min 48 sec = 6048 sec.
Given time is: 1 hr 40 min 48 sec.
Conver hr to sec.
First convert hr to min : 1 hr = 60 min.
Next convert min to sec : 60 min = 3600 sec (1 min = 60 sec).
Finally 1 hr = 3600 sec.
Convert min to sec.
40 min = 40*60 sec = 2400 sec.
Then add 3600+2400+48 = 6048 sec.
1 hr 40 min 48 sec = 6048 sec.
Azly said:
9 years ago
Here, the car has been travelled 42 km in 1.68 hours.
Find the distance travelled in 1 hour.
42/1.68*1 = 25 km/h.
25km/h is 5/7 of the actual speed.
Then, 25/5*7 = 35 km/h.
Find the distance travelled in 1 hour.
42/1.68*1 = 25 km/h.
25km/h is 5/7 of the actual speed.
Then, 25/5*7 = 35 km/h.
Rakeshgatla jgtl said:
9 years ago
Hello, clear your doubts with my explanations 40 minutes 40/60 = 2/3 and take 48 seconds.
48 / 60 * 60 = 1/75.
1 hour 40 minutes 48 seconds = 1 + 2/3 + 1/75 = 126/75 = 42/25.
Clear your doubts with my explanations.
48 / 60 * 60 = 1/75.
1 hour 40 minutes 48 seconds = 1 + 2/3 + 1/75 = 126/75 = 42/25.
Clear your doubts with my explanations.
Atchu said:
9 years ago
Lets the speed be (5/7) x.
Distance 42 km and Time (after converted into hr) = 1.68hr.
Speed = distance/time.
(5/7) x = 42/1.68.
(5/7) x = 25.
x = 25*7/5.
x =35km/hr.
Distance 42 km and Time (after converted into hr) = 1.68hr.
Speed = distance/time.
(5/7) x = 42/1.68.
(5/7) x = 25.
x = 25*7/5.
x =35km/hr.
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