In this task, you need to answer the given multiple-choice question on the gain. Gain is the value by which to multiply the input. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Q: Problem: mary works in a restaurant a maximum of 70 hours . for the first 20 hours , she is paid $ 8 per hour . for each overtime hour , she is paid at a rate which is 25 % higher than her regular rate . how much mary can earn in a week ? 
Options: a ) 600 , b ) 620 , c ) 660 , d ) 320 , e ) 400

A: c
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Q: Problem: a trader mixes 80 kg of tea at 15 per kg with 20 kg of tea at cost price of 20 per kg . in order to earn a profit of 50 % , what should be the sale price of the mixed tea ? 
Options: a ) 23.75 , b ) 22 , c ) 20 , d ) 19.2 , e ) none of these

A: e
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Q: Problem: running at the same constant rate , 6 identical machines can produce a total of 300 bottles per minute . at this rate , how many bottles could 10 such machines produce in 4 minutes ? 
Options: a ) 648 , b ) 1800 , c ) 2000 , d ) 10800 , e ) 10900

A:
c
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