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'.

[EX Q]: Problem: joan and karl each bought a telescopes and the sum of their purchases was $ 400 . if twice of what joan paid was $ 74 more than what karl paid , what did joan pay for her telescope ? 
Options: a ) $ 150 , b ) $ 152 , c ) $ 154 , d ) $ 156 , e ) $ 158
[EX A]: e

[EX Q]: Problem: find the number which multiplied by 15 is increased by 196 . 
Options: a ) 14 , b ) 20 , c ) 26 , d ) 28 , e ) 27
[EX A]: a

[EX Q]: Problem: if ( x + yi ) / i = ( 7 + 9 i ) , where x and y are real , what is the value of ( x + yi ) ( x - yi ) ? 
Options: a ) 110 , b ) 120 , c ) 130 , d ) 140 , e ) 150
[EX A]:
c