To cover a distance of 832 km a train A takes 2\(\frac{2}{3}\) hours more than train B. If the speed of A is doubled, it would take 1\(\frac{1}{3}\) hour less than B. What is the speed (in km/h) of train B?
Answer & explanation
Correct answer: option 2
SpeedA = 1 : 2
TimeA = 2 : 1 (since distance covered is same)
l_____l
1 → 2\(\frac{2}{3}\) + 1\(\frac{1}{3}\) =\(\frac{8}{3}\) + \(\frac{4}{3}\) = 4
1 → 4 hour
When A's speed is double, A takes 4 hours
Therefore ATQ,
B takes = 4 + 1\(\frac{1}{3}\) = 5\(\frac{1}{3}\) = \(\frac{16}{3}\)
SB = \(\frac{832 × 3}{16}\) = 156 km/h