Aptitude - Time and Distance - Discussion
Discussion Forum : Time and Distance - General Questions (Q.No. 2)
2.
An aeroplane covers a certain distance at a speed of 240 kmph in 5 hours. To cover the same distance in 1
hours, it must travel at a speed of:
hours, it must travel at a speed of:Answer: Option
Explanation:
Distance = (240 x 5) = 1200 km.
Speed = Distance/Time
Speed = 1200/(5/3) km/hr. [We can write 1 hours as 5/3 hours]
 Required speed = |
 |
1200 x | 3 |  km/hr |
= 720 km/hr. |
| 5 |
Discussion:
160 comments Page 5 of 16.
Veeresh said:
1 decade ago
Why we should write 5/3 as 3/5?
Vijay said:
1 decade ago
Speed = distance/time.
Distance = same.
Speed S1 = 240, Speed S2=?
Time t1 = 5hours, time t2 = 3/5hours.
S1/S2 = t2*t1.
240/S2 = (3/5)/5.
S2 = 720 kmph.
Distance = same.
Speed S1 = 240, Speed S2=?
Time t1 = 5hours, time t2 = 3/5hours.
S1/S2 = t2*t1.
240/S2 = (3/5)/5.
S2 = 720 kmph.
Vinayaga said:
1 decade ago
Why we use 1+2/3 ?
Udaya said:
1 decade ago
This can also be solved as:
Given d1 = d2.
=> s1*t1 = s2*t2.
240*5 = s2*5/3.
s2 = 240*5*3/5.
s2 = 720 kmph.
Given d1 = d2.
=> s1*t1 = s2*t2.
240*5 = s2*5/3.
s2 = 240*5*3/5.
s2 = 720 kmph.
JEEVA said:
1 decade ago
240km--------5hr.
? --------5/3hr.
240*5/5/3 the 5/3 become 3/5 when it come up, the 5 can cut.
So finally we can 240*3 = 720kmph.
? --------5/3hr.
240*5/5/3 the 5/3 become 3/5 when it come up, the 5 can cut.
So finally we can 240*3 = 720kmph.
Jabi Mir said:
1 decade ago
Here, V1 = 240 km/h, T1 = 5 h, Also, V2= ?, T2 = 5/3.
We Know, V=S/T or S = VxT, But here distance is same,
Therefore, V1xT1=V2xT2, rearranging we get, V2 = V1xT1/T2.
Substituting values,
V2 = 240 x 5 / 5/3 or we can write it, V2 = 240 x 5 x 3/5.
On simplifying we get, V2=720 Km/h.
We Know, V=S/T or S = VxT, But here distance is same,
Therefore, V1xT1=V2xT2, rearranging we get, V2 = V1xT1/T2.
Substituting values,
V2 = 240 x 5 / 5/3 or we can write it, V2 = 240 x 5 x 3/5.
On simplifying we get, V2=720 Km/h.
(1)
Manasa said:
1 decade ago
1 hr become 5/3hr as:
1 hr is 1/3 rd of part in 5hrs that means 1 = 3/3.
1 = (5-2)/3, 1 = (5/3)-(2/3), 1+(2/3) = 5/3,
Then 5/3 = 5/3.
Here it is proved 1hr is 1/3rd of part in 5hrs.
1 hr is 1/3 rd of part in 5hrs that means 1 = 3/3.
1 = (5-2)/3, 1 = (5/3)-(2/3), 1+(2/3) = 5/3,
Then 5/3 = 5/3.
Here it is proved 1hr is 1/3rd of part in 5hrs.
Divyan said:
1 decade ago
Why we are multiplying 240*5?
Because they 5hrs right. So it has to be 5*3600 right.
Because they 5hrs right. So it has to be 5*3600 right.
Veerapandi E said:
1 decade ago
How come 5/3?
Dhanshri said:
1 decade ago
s = d/t.
s1 = d1/t1.
s2 = d2/t2.
s1t1 = s2t2/distance is same.
t2 = s1t1/s2.
t2 = 240*5/(5/3).
t2 = 720.
s1 = d1/t1.
s2 = d2/t2.
s1t1 = s2t2/distance is same.
t2 = s1t1/s2.
t2 = 240*5/(5/3).
t2 = 720.
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