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 49 hours respectively. The ratio of their speeds is? Pick:
A) 4:5 B) 7:3 C) 4:4 D) 7:8 E) 7:1
Let us name the trains A and B.   Then, (A's speed) : (7:3's speed)   = √b : √a = √49 : √9   = 7:3   Answer: 7:3
<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 49 hours respectively. The ratio of their speeds is?