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: in arun ’ s opinion , his weight is greater than 65 kg but less than 72 kg . his brother doest not agree with arun and he thinks that arun ’ s weight is greater than 60 kg but less than 70 kg . his mother ’ s view is that his weight can not be greater than 68 kg . if all are them are correct in their estimation , what is the average of different probable weights of arun ? 
Options: a ) 66 kg , b ) 67 kg , c ) 68 kg , d ) 69 kg , e ) none of these
[EX A]: b

[EX Q]: Problem: if x is real , find the maximum value of the expression - 2 x ^ 2 + 5 x + 7 . 
Options: a ) 6.125 , b ) 8.125 , c ) 10.125 , d ) 12.125 , e ) 14.125
[EX A]: c

[EX Q]: Problem: what is the value of x ^ 2 yz − xyz ^ 2 , if x = - 1 , y = 1 , and z = 3 ? 
Options: a ) 20 , b ) 24 , c ) 30 , d ) 12 , e ) 48
[EX A]:
d