Bunuel wrote:
If the ratio of the lengths of two trains is 2 : 3 and the ratio of the times taken by them to completely cross each other when travelling in the same direction and when travelling in opposite directions is 4 : 1, what is the ratio of the speed of the faster train to the speed of the slower train?
A. 5 : 2
B. 5 : 3
C. 3 : 2
D. 5 : 4
E. 7 :6
Let the length of the train = 2x and 3x respectively
The speed of the faster train =\(s_1\)
The speed of the slower train =\(s_2\)
When the trains cross, the total distance covered = Sum of the individual lengths =\( 2x + 3x =5x\)
\( \frac{\frac{5x}{s_1-s_2}}{\frac{5x}{s_1+s_2}} =\frac{4}{1}\)
\( \frac{s_1+s_2}{s_1-s_2} =\frac{4}{1}\)
\( s_1 + s_2 = 4s_1 -4s_2\)
\( 5s_2 =3s_1\)
\(\frac{5}{3} =\frac{s_1}{s_2}\)
OptionB
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Statistics : Posted by gmatophobia • on 20 Sep 2023, 06:00 • Replies 1 • Views 110
