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: a can do a piece of work in 4 hours ; b and c together can do it in 3 hours , which a and c together can do it in 2 hours . how long will b alone take to do it ? 
Options: a ) 15 hours , b ) 14 hours , c ) 12 hours , d ) 74 hours , e ) 79 hours

Answer: c


Question: Problem: a metallic sphere of radius 12 cm is melted and drawn into a wire , whose radius of cross section is 8 cm . what is the length of the wire ? 
Options: a ) 16 cm , b ) 24 cm , c ) 28 cm , d ) 36 cm , e ) 39 cm

Answer: d


Question: Problem: how much time will a train of length 200 m moving at a speed of 72 kmph take to cross another train of length 300 m , moving at 36 kmph in the same direction ? 
Options: a ) 50 sec , b ) 26 sec , c ) 80 sec , d ) 82 sec , e ) 81 sec

Answer:
a