In this task, you need to answer the given multiple-choice question on the general math. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Q: Problem: the average age of 15 students of a class is 15 years . out of these , the average age of 8 students is 14 years and that of the other 6 students is 16 years , the age of the 15 th student is 
Options: a ) 17 , b ) 12 , c ) 13 , d ) 14 , e ) 15

A: a
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Q: Problem: how many paying stones , each measuring 2 1 / 2 m * 2 m are required to pave a rectangular court yard 20 m long and 16 1 / 2 m board ? 
Options: a ) 66 , b ) 18 , c ) 16 , d ) 10 , e ) 15

A: a
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Q: Problem: the avg weight of a , b & c is 70 kg . if d joins the group , the avg weight of the group becomes 70 kg . if another man e who weights is 3 kg more than d replaces a , then the avgof b , c , d & e becomes 68 kg . what is the weight of a ? 
Options: a ) 81 , b ) 65 , c ) 75 , d ) 89 , e ) 90

A:
a
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