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 4 hours and 9 hours respectively. The ratio of their speeds is	Choose the correct choice from the following:
A) 3 : 2
B) 4 : 3
C) 4 : 7
D) 8 : 5
E) None
Sol.   Let us name the trains as A and B. Then,   (A's speed) : (B's speed) = √b : √a   = √9 : √4   = 3 : 2.   3 : 2nswer 3 : 2
<result>A</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 4 hours and 9 hours respectively. The ratio of their speeds is