Two trains A and B starting from two points and travelling in opposite directions, reach their destinations 9 hours and 16 hours respectively after meeting each other. If the train A travels at 80kmph, find the rate at which the train B runs. Choose the correct choice from the following options:  A) 40  B) 160  C) 120  D) 80  E) 100
If two objects A and B start simultaneously from opposite points and, after meeting, reach their destinations in ‘a’ and ‘b’ hours respectively (i.e. A takes ‘a hrs’ to travel from the meeting point to his destination and B takes ‘b hrs’ to travel from the meeting point to his destination), then the ratio of their speeds is given by:   Sa/Sb = √(b/a)   i.e. Ratio of speeds is given by the square root of the inverse ratio of time taken.   Sa/Sb = √(4/16) = 2/4=1/2   This gives us that the ratio of the speed of A : speed of B as 1:2.   Since speed of A is 80 kmph, speed of 160 must be 80*(2/1)= 
<gadget id="calculator">80*(2/1)</gadget>
<output>160</output>
160 kmph   160
<result>B</result>
Two trains A and B starting from two points and travelling in opposite directions, reach their destinations 9 hours and 16 hours respectively after meeting each other. If the train A travels at 80kmph, find the rate at which the train B runs.