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 36 hours respectively. The ratio of their speeds is?	Pick one: A) 4:5 B) 4:3 C) 4:4 D) 4:9 E) 6:3
Let us name the trains A and B.   Then, (A's speed) : (B's speed)   = √b : √a = √36 : √9 = 6:3   Answer:6:3
<result>E</result>
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 36 hours respectively. The ratio of their speeds is?