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 choices.
A) 2 : 3
B) 4 : 3
C) 6 : 7
D) 9 : 16
E) none

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