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: a couple spent $ 211.20 in total while dining out and paid this amount using a credit card . the $ 211.20 figure included a 20 percent tip which was paid on top of the price which already included a sales tax of 10 percent on top of the price of the food . what was the actual price of the food before tax and tip ? 
Options: a ) $ 120 , b ) $ 140 , c ) $ 150 , d ) $ 160 , e ) $ 180
[A]: d


[Q]: Problem: the population of a bacteria culture doubles every 2 minutes . approximately how many minutes will it take for the population to grow from 1,000 to 100,000 bacteria 
Options: a ) 10 , b ) 12 , c ) 14 , d ) 16 , e ) 18
[A]: c


[Q]: Problem: if 9 ^ y = 3 ^ 12 , what is y ? 
Options: a ) 2 , b ) 3 , c ) 4 , d ) 5 , e ) 6
[A]:
e