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 from the following options
A) 2 : 3 B) 4 : 3 C) 6 : 7 D) 9 : 16 E) none of these

Rationale: "let us name the trains as a and b . then , ( a ' s speed ) : ( b ' s speed ) = √ b : √ a = √ 16 : √ 9 = 4 : 3 . answer b"
Answer: B