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 80 days and b in 100 days . they work together for 20 days and then b goes away . in how many days will a finish the remaining work ?
Options: a ) 33 days , b ) 44 days , c ) 55 days , d ) 42 days , e ) 32 days

Answer: b

Question: Problem: today mary ' s father is 4 times as old as mary . 3 years ago , he was 5 times as old . how old is mary today ?
Options: a ) 6 , b ) 8 , c ) 10 , d ) 12 , e ) 14

Answer: d

Question: Problem: if john covers a certain distance in 1 hr . 24 min . by covering two third of the distance at 4 kmph and the rest at 5 kmph , then find the total distance .
Options: a ) 9 km , b ) 2 km , c ) 1 km , d ) 6 km , e ) 7 km

Answer:
d