manishtank1988 wrote:
How can anyone break 4 into 4/3 and 8/3 as per 2nd statement?
What i want to ask is that what is the though process behind it because i can understand what you have done but i don't know what to do so that i can myself learn to break a integer in fraction as that in other cases. So if possible PLEASE elaborate.
Thanks
Hi,
Consider this as follows:
Statement 2 says the average speed in the 1st half(Say S1) was twice the average speed in the 2nd half(say S2)
Or S1 = 2(S2)
Now, Time taken for 1st half = Distance(d)/Speed(S1) = d/S1 = d/2(S2) -- (1)
Time taken for 2nd half = Distance(d)/Speed(S2) = d/S2 -- (2)
Total Time Taken : (1) + (2) = d/S2 (3/2) (I hope you are clear on this.)
Total Distance = 2d
Average Speed of Entire Journey = Total Distance/Total Time Taken = 2d/(d/S2) (3/2) = 4/3S2.
Since we have an unknown variable S2 in the equation, we can B is not sufficient. We need the value of S2, which cannot be derived using A even. Hence Answer is E.
We have got 4/3 as per above solution and as we know that Speed is inversely proportional to time. So, for a given distance, when speed is doubled, it means time would be half and vice versa.
Let me know in case of any confusion.