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21 Jun 2021, 02:45
Kudos
Bookmarks
B
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
75%
(hard)
Question Stats:
64% (02:49) correct
36%
(03:08)
wrong
based on 272
sessions
History
Date
Time
Result
Not Attempted Yet
After travelling a distance of 180 km, a train met with an accident and then travelled at 3/4 of its original speed. It was 1 hour late in reaching its destination. If the accident had occurred a further 60 km on from the place of the accident, the delay would have been only 30 minutes. What is the total distance travelled by the train?
(A) 200 km
(B) 300 km
(C) 400 km
(D) 500 km
(E) 600 km
(A) 200 km
(B) 300 km
(C) 400 km
(D) 500 km
(E) 600 km
05 Jul 2021, 06:16
Kudos
Bookmarks
Bunuel
Let original speed be \(4x\) then reduced speed is \(3x \)
Let Distance travelled after accident be \(D\)
\(\frac{D}{3x} - \frac{D}{4x} = 1\)
\(\frac{D}{x} =12 \)
\(x= \frac{D}{12} \hspace{2 mm} (i)\)
If the accident had occurred \(60\) Km further on, then after accident train would now have travelled \(D-60 \)
\(\frac{D -60}{3x} - \frac{D - 60}{4x} = \frac{1}{2} \)
On solving we get :
\( D- 60 =6x \hspace{2 mm} (ii )\)
\( D - 60 = 6*\frac{D}{12 }\) - > Substituting the value of \(x\) from \((i)\) into \((ii)\)
\(2D -120 = D \)
\(D= 120 \)
So total distance = distance before accident + distance after accident = \(180 +120 = 300\)
Ans-B
Hope it's clear.
09 Jul 2021, 05:29
Kudos
Bookmarks
I think we can solve this question without the calculations. Because if the total Distance is D, then to cover the remaining distance after 180 km i.e (D-180) the train travelled at 3/4 of its original speed. And further it is stated that if the accident had occurred a further 60 km on from the place of the accident, the delay would have been only 30 minutes which means in this case the remaining distance has been reduced by 60 kms i.e (D-240) and this distance was covered by the train at the same speed as before i.e 3/4 of its original speed. Which essentially means if we add another 60 kms to the above distance the train would have reached on time. Hence, 240+60 = 300 kms (B)
By adding 60 kms to the 180 kms, the remaining distance is being halved and hence, the time is halved.
By adding 60 kms to the 180 kms, the remaining distance is being halved and hence, the time is halved.
