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: two diagonals of a rhombus are 72 cm and 30 cm respectively . what is its perimeter ?
Options: ['a ) 136 cm', 'b ) 156 cm', 'c ) 144 cm', 'd ) 121 cm', 'e ) 126 cm']

Answer: b

Question: Problem: a and b are two stations 390 km apart . a train starts from a at 10 a . m . and travels towards b at 65 kmph . another train starts from b at 11 a . m . and travels towards a at 35 kmph . at what time do they meet ?
Options: a ) 2.15 pm , b ) 1.15 pm , c ) 4.15 pm , d ) 3.15 pm , e ) 12.15 pm

Answer:
a