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 river boat leaves silver town and travels upstream to gold town at an average speed of 6 kilometers per hour . it returns by the same route at an average speed of 5 kilometers per hour . what is the average speed for the round - trip in kilometers per hour ?
Options: a ) 5.5 , b ) 7.1 , c ) 7.2 , d ) 7.0 , e ) 8.0

Answer: a

Question: Problem: mariah has decided to hire three workers . to determine whom she will hire , she has selected a group of 12 candidates . she plans to have one working interview with 3 of the 12 candidates every day to see how well they work together . how many days will it take her to have working interviews with all the different combinations of job candidates ?
Options: a ) 720 , b ) 120 , c ) 300 , d ) 30 , e ) 333

Answer: c

Question: Problem: maria sold 10 kg of apples in her first hour at the market , but only 2 kg of apples in the second hour . on average , how many kg of apples did she sell in two hours at the market ?
Options: a ) 6 kg , b ) 5 kg , c ) 12 kg , d ) 24 kg , e ) 20 kg

Answer:
a