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:
300 kmph
360 kmph
600 kmph
720 kmph
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:
162 comments Page 5 of 17.

Vaidik said:   5 years ago
According to the tri-rashi method.

5hours ----------->240km/h.
5/3hours ---------> (?).

5 x 240/5 x3 =80kmph.

I know this is wrong but speed should increase here because time is decreasing but I want to know why this method is not applicable here. Please can anyone help me to solve this?
(2)

Haroon Baloch said:   2 months ago
First, we need to find the distance covered by the plane.
Distance = Speed × Time
= 240 kmph × 5 hours = 1200 km.

Now, we want the plane to cover 1200 km in 1^2/3 hours (or 5/3 hours).
New Speed = Distance/Time = 1200 km /(5/3) hours = 1200 × 3/5 = 720 kmph.

So, the plane must travel at 720 kmph.
(2)

Srinivasan.S said:   2 decades ago
The distance wants cover with 1+(2/3)hour is 1200km.

1 + (2/3) = (3+2)/3 = 5/3.

speed=Distance/time
speed=1200km/(5/3)
speed=1200km*(3/5)
speed=720km/hr
(1)

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.
(1)

Sujatha said:   7 years ago
1(2/3)is written as 1+(2/3)=(3*1+2)/3=(3+2)/3=5/3.
now we solve s=d/t,
S=1200/(5/3),
S=1200*3/5,
S=720.
(1)

Aditi said:   5 years ago
Why 240 x 5?
(1)

Mohammed Yahiya Khan said:   1 month ago
Very good to learn and understand the solution.
(1)

Vino said:   2 decades ago
How to give 3/5 ?

Shwetha shree said:   2 decades ago
D= S*T that's why 240 * 5.

Sree said:   2 decades ago
Hello! Shwetha, You want to take it as comparison of two plan.

First Plan : 240km * 5hr = 1200km/hr
Second Plan: ? *1+(2/3)= 1200km/hr


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