Teacher: 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'.
Teacher: Now, understand the problem? If you are still confused, see the following example:
Problem: what is difference between biggest and smallest fraction among 2 / 3 , 3 / 4 , 4 / 5 and 5 / 3
Options: a ) 2 / 5 , b ) 3 / 5 , c ) 1 / 6 , d ) 1 , e ) none of these
Solution: d
Reason: "explanation : 2 / 3 = . 66 , 3 / 4 = . 75 , 4 / 5 = . 8 and 5 / 3 = 1.66 so the biggest is 5 / 3 and the smallest is 2 / 3 their difference is 5 / 3 - 2 / 3 = 3 / 3 = 1 option d"

Now, solve this instance: Problem: there is an antique clock exhibition . so many clock are piled up with distinct numbers tagged with them . the person managing it hangs different clocks numbers periodically on the main wall . at 9 : 20 am , he hung the clock number 200 ; at 11 : 00 am , he hung the clock number 30 ; at 4 : 00 pm , he hung the clock number 240 . which numbered clock will he hang on the wall when the time is 7 : 30 pm ?
Options: a ) 313 , b ) 314 , c ) 315 , d ) 316 , e ) 317
Student:
c