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 4 of 12.
Varshini said:
5 years ago
1hr 40min 40sec = (60x60) + (40x60) + 48.
3600 + 2400 + 48.
6048.
Now converting into the min and then to hr.
6048/60 = 100.8 min.
100.8/60 = 1.68 hr
3600 + 2400 + 48.
6048.
Now converting into the min and then to hr.
6048/60 = 100.8 min.
100.8/60 = 1.68 hr
(2)
Kalaiyarasan said:
4 years ago
Time taken = 1hr 40min 48sec.
= 1hr 40*4/5 min =1 * 17/25hr = 17/25 hr.
Time = 42/25 hr ,
Actual speed = 5/7 * x,
distance=42.
s = d/t.
5/7 * x = 42 * 25/42
x = 25 * 7/5,
x = 35km/hr.
= 1hr 40*4/5 min =1 * 17/25hr = 17/25 hr.
Time = 42/25 hr ,
Actual speed = 5/7 * x,
distance=42.
s = d/t.
5/7 * x = 42 * 25/42
x = 25 * 7/5,
x = 35km/hr.
Manish tiwari said:
1 decade ago
1 hr 40min 48 sec = 1 + 40/60 + 48/(60*60) hrs
=1+ 2/3 + 4/300
=(300+200+4)/300
=504/300
=126/75
Please sidharth can explain the answer please as 35 km/ph and =(300+200+4)/300 this step.
Thanks.
=1+ 2/3 + 4/300
=(300+200+4)/300
=504/300
=126/75
Please sidharth can explain the answer please as 35 km/ph and =(300+200+4)/300 this step.
Thanks.
Kasaiah said:
9 years ago
Hello here speed equals to distance by time.
Then 5x/7 = 42/126/75
It form as, 5x/7 * 75/126 = 42
But solution is above mentioned is not matched with my answer. Anyone explain it please.
Thanks
Then 5x/7 = 42/126/75
It form as, 5x/7 * 75/126 = 42
But solution is above mentioned is not matched with my answer. Anyone explain it please.
Thanks
Krishna said:
9 years ago
Hello, They have given that speeds ratio 7 : 5 ie, 7x, 5x.
Hence second time speed gave ie,, 42/126/75 = 42 * 75/126 = 25.
5x = 25.
x = 5.
7x = 35.
Thank you, I hope you all understand.
Hence second time speed gave ie,, 42/126/75 = 42 * 75/126 = 25.
5x = 25.
x = 5.
7x = 35.
Thank you, I hope you all understand.
Tisha said:
1 decade ago
first convert the time in hours format,
i.e 1 hour 40 mins 48 secs = 1+(40/60)+(48/(60*60)) = 126/75.
Hence time = 126/75 hrs,
w.k.t, s = d/t;
s = 42/ (126/75) (5/7).
s = 35 km/hr.
i.e 1 hour 40 mins 48 secs = 1+(40/60)+(48/(60*60)) = 126/75.
Hence time = 126/75 hrs,
w.k.t, s = d/t;
s = 42/ (126/75) (5/7).
s = 35 km/hr.
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.
Dhivya said:
2 years ago
T = 1hr40min48sec.
= 1hr40(48/60)min,
= 1hr40(4/5)min,
= 1hr(204/5*60)min,
= 1(51/75)hr,
= 126/75 hr,
Then, Actual speed = (5/7x)*(126/75) = 42.
X = (42*7*75/15*126) = 35km/hr.
= 1hr40(48/60)min,
= 1hr40(4/5)min,
= 1hr(204/5*60)min,
= 1(51/75)hr,
= 126/75 hr,
Then, Actual speed = (5/7x)*(126/75) = 42.
X = (42*7*75/15*126) = 35km/hr.
(34)
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.
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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