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'.
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Question: Problem: the ratio between the speeds of two trains is 7 : 8 . if the second train runs 400 km in 4 hours , what is the the speed of the first train ? 
Options: a ) 87.0 , b ) 87.5 , c ) 87.2 , d ) 87.1 , e ) 87.4

Answer: b


Question: Problem: an seller earns an income of re 1 on the first day of his business . on every subsequent day , he earns an income which is just thrice of that made on the previous day . on the 20 th day of business , he earns an income of : 
Options: a ) 29 , b ) 57 , c ) 35 , d ) 20 , e ) 30

Answer: b


Question: Problem: how many seconds will a 650 meter long train moving with a speed of 63 km / hr take to cross a man walking with a speed of 3 km / hr in the direction of the train ? 
Options: a ) 48 , b ) 36 , c ) 26 , d ) 39 , e ) 18

Answer:
d