Two, trains, one from Howrah to Patna and the other from Patna to Howrah, start simultaneously. After they meet, the trains reach their destinations after 9 hours and 16 hours respectively. The ratio of their speeds is:
Choose the correct choice:
A) 2 : 3
B) 4 : 3
C) 6 : 7
D) 9 : 16
E) 9 : 14

Rationale: let the slower train have speed of 1 unit and faster train a speed of r units of speed . let t = time to when the trains meet . rt 1 t howrah | - - - - - - - - - - - - - - - - - - - - - - - | - - - - - - - - - - | patna meet they meet rt units from howrah and 1 t units from patna for the second part of the journey the fast train at speed r has 1 t unit of distance and 9 hours to do it so 1 t / r = 9 slow train has rt units of distance at speed of 1 unit and 16 hours to do it . rt / 1 = 16 so rt / 1 16 - - - - - = - - - - giving r ^ 2 = 16 / 9 1 t / r 9 r = 4 / 3 answer : b
Answer: B