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'.

Q: Problem: a and b together can do a work in 4 days . if a alone can do it in 20 days . in how many days can b alone do it ? 
Options: a ) 11 , b ) 5 , c ) 6 , d ) 8 , e ) 25

A: b
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Q: Problem: in a 500 m race , the ratio of the speeds of two contestants a and b is 3 : 4 . a has a start of 155 m . then , a wins by : 
Options: a ) 60 m , b ) 20 m , c ) 40 m , d ) 20 m , e ) 23 m

A: c
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Q: Problem: a train 150 m long passes a km stone in 15 seconds and another train of the same length travelling in opposite direction in 8 seconds . the speed of the second train is 
Options: a ) 60 kmph , b ) 66 kmph , c ) 72 kmph , d ) 99 kmph , e ) 89 kmph

A:
d
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