Distance between 2 places A and B is given. A man P starts from place A at 9 pm and another man Q goes from B at 10 p.m. Speed of Q is double of that of P. Both cover 1/4 dist in the same time interval then A travels the entire dist in time?

8 hours

Interview Candidate
Jun 21st, 2005
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anubhav

Aug 3rd, 2006

There are two points a and b

let the distance between them is x

now they are covering 1/4th of the distance in same time

so let after y hours of starting of b they will meet

so the equation will be as follows

Q*y=1/4x

Q/2*y=1/4x

so we will get

q/2*y=q*y

2y=y+1

y=1

but for ‘a’ it will complete this in 2hours

so it will complete the 1/4th distance in 2 hours

so it will cover full distance in 8 hours

priyanka

Nov 14th, 2006

answer is 8 hours...
the distance covered by both is constant, lets say "D", and let total path = 2D
for P, then, time taken to cover this distance D is 1 hour more than Q takes, beacuse P started at 9, and Q started at 10
so for A = time = T+1, speed = x Km/hour, distance = D
and for B, time = T, speed = 2x Km/hour, distance = D
as distance = speed * time , which is D in this case, we have:
(T + 1)x = 2xT
T -2T + 1 = 0
or T = 1.... thus , since Q takes 1 hour to cover the distance, P takes 2 hours to cover it.....(D)..to cover the whole distance then, he takes 4*2 = 8 hours (answer)