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: if 7 ^ k = 2 , then 7 ^ ( 4 k + 2 ) =
Options: a ) 729 , b ) 754 , c ) 784 , d ) 783 , e ) 108
c

Problem: if a * b * c = ( ( a + 2 ) ( b + 3 ) ) / ( c + 1 ) , find the value of 6 * 15 * 2 .
Options: a ) 8 , b ) 5 , c ) 11 , d ) 3 , e ) 4
e

Problem: john want to buy a $ 100 trouser at the store , but he think it a ™️ s too expensive . finally , it goes on sale for $ 55 . what is the percent decrease ?
Options: a ) 20 % , b ) 30 % , c ) 40 % , d ) 50 % , e ) 45 %
e