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'.

Problem: a certain lab experiments with white and brown mice only . in one experiment , 2 / 3 of the mice are white . if there are 11 brown mice in the experiment , how many mice in total are in the experiment ? 
Options: a ) 39 , b ) 33 , c ) 26 , d ) 21 , e ) 10
b

Problem: for any integer k greater than 1 , the symbol k * denotes the product of all integers between 1 and k , inclusive . if k * is a multiple of 315 what is the least possible value of k ? 
Options: a ) 5 , b ) 7 , c ) 9 , d ) 11 , e ) 13
b

Problem: on a certain date , pat invested $ 10,000 at x percent annual interest , compounded annually . if the total value of the investment plus interest at the end of 12 years will be $ 40,000 , in how many years , the total value of the investment plus interest will increase to $ 320,000 ? 
Options: a ) 30 , b ) 16 , c ) 18 , d ) 20 , e ) 24

a