In this task, you need to provide the correct option for a given problem from the provided options.

Q: Problem: if 30 % of the 880 students at a certain college are enrolled in biology classes , how many students at the college are not enrolled in a biology class ? 
Options: a ) 620 , b ) 630 , c ) 616 , d ) 600 , e ) 650

A: c
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Q: Problem: a can contains a mixture of liquids a and b is the ratio 7 : 5 . when 9 litres of mixture are drawn off and the can is filled with b , the ratio of a and b becomes 7 : 9 . how many liter e of liquid a was contained by the can initially ? 
Options: a ) 10 , b ) 20 , c ) 21 , d ) 25 , e ) 27

A: c
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Q: Problem: find the ratio in which rice at rs . 7.20 a kg be mixed with rice at rs . 5.50 a kg to produce a mixture worth rs . 6.30 a kg 
Options: a ) 2 : 0 , b ) 2 : 3 , c ) 2 : 1 , d ) 8 : 9 , e ) 2 : 8

A:
d
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