In this task, you need to answer the given multiple-choice question on the physics. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Problem: a can do a piece of work in 18 days and b alone can do it in 10 days . b works at it for 5 days and then leaves . a alone can finish the remaining work in 
Options: a ) 5 days , b ) 6 days , c ) 7.5 days , d ) 8.5 days , e ) 9 days
e

Problem: in a 80 meters race a beats b by 56 m or 7 seconds . a ' s time over the course is : 
Options: a ) 3 seconds , b ) 12 seconds , c ) 10 seconds , d ) 18 seconds , e ) 28 seconds
a

Problem: a train leaves delhi at 7 a . m . at a speed of 30 kmph . another train leaves at 2 p . m . at a speed of 40 kmph on the same day and in the same direction . how far from delhi , will the two trains meet ? 
Options: a ) 229 , b ) 840 , c ) 600 , d ) 888 , e ) 121

b