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 can finish a work in 12 days , b in 9 days and c in 2 days , b and c start the work but are forced to leave after 3 days . the remaining work was done by a in ? 
Options: a ) 10 days , b ) 12 days , c ) 6 days , d ) 7 days , e ) 5 days

A: e
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Q: Problem: the length of a room is 5.5 m and width is 3.75 m . what is the cost of paying the floor by slabs at the rate of $ 300 per sq . metre . 
Options: a ) $ 2587.50 , b ) $ 3587.50 , c ) $ 4187.50 , d ) $ 6187.50 , e ) $ 8587.50

A: d
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Q: Problem: pipe p can fill a tank in 8 hours , pipe q in 12 hours and pipe r in 20 hours . if all the pipes are open , in how many hours will the tank be filled ? 
Options: a ) 2 hours , b ) 2.4 hours , c ) 3.8 hours , d ) 3.5 hours , e ) 4.5 hours

A:
c
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