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 answer.
A) 2 : 3
B) 4 : 3
C) 6 : 7
D) 9 : 16
E) None
Sol.   Let us name the trains as A and B. Then,   (A's speed) : (B's speed) = √b : √a   = √16 : √9   = 4 : 3.   Answer 4 : 3
<result>B</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 16 hours respectively. The ratio of their speeds is