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: if a person walks at 20 km / hr instead of 10 km / hr , he would have walked 20 km more . the actual distance traveled by him is : 
Options: a ) 20 km , b ) 56 km , c ) 60 km , d ) 70 km , e ) 80 km
[EX A]: a

[EX Q]: Problem: the sum of all the integers k such that – 25 < k < 24 is 
Options: a ) 0 , b ) - 2 , c ) - 25 , d ) - 49 , e ) - 47
[EX A]: e

[EX Q]: Problem: the visitors of a modern art museum who watched a certain picasso painting were asked to fill in a short questionnaire indicating whether they had enjoyed looking at the picture and whether they felt they had understood it . according to the results of the survey , all 100 visitors who did not enjoy the painting also did not feel they had understood the painting , and the number of visitors who enjoyed the painting was equal to the number of visitors who felt they had understood the painting . if 3 / 4 of the visitors who answered the questionnaire both enjoyed the painting and felt they had understood the painting , then how many visitors answered the questionnaire ? 
Options: a ) 90 , b ) 120 , c ) 160 , d ) 360 , e ) 400
[EX A]:
e