During a behavioral experiment in a psychology class, each student is asked to compute his or her lucky number by raising 7 to the power of the student's favorite day of the week (numbered 1 through 7 for Monday through Sunday respectively), multiplying the result by 3, and adding this to the doubled age of the student in years, rounded to the nearest year. If a class consists of 28 students, what is the probability that the median lucky number in the class will be a non-integer?  Choose the correct choice from the following choices
A) 0%  B) 10%  C) 20%  D) 30%  E) 40%
Student's age is integral value. In question, we are multiplying student's age by 2 and adding some 3* 7^x something over there.   It means Even (2* age of students) + Odd (3) * 7 ^x (where x is day of week).   We know that 7^x is always odd. (e.g. 7, 49, 243, 1701, and repeat).   =&gt; 3* odd is again odd.   2 * age of students is always even.   So final equation is even +odd = odd.   Avg of any number of odd digits or any number of even digits can never be non integral value. So 0% is the answer 0%.
<result>A</result>
During a behavioral experiment in a psychology class, each student is asked to compute his or her lucky number by raising 7 to the power of the student's favorite day of the week (numbered 1 through 7 for Monday through Sunday respectively), multiplying the result by 3, and adding this to the doubled age of the student in years, rounded to the nearest year. If a class consists of 28 students, what is the probability that the median lucky number in the class will be a non-integer?