The task is to generate the correct answer for a given math problem.

Problem: two trains of length 100 meters and 200 meters are 450 meters apart . they are moving towards each other on parallel tracks , at speeds of 90 km / h and 72 km / h . after how many seconds will the trains meet ?
10

Problem: in traveling from a dormitory to a certain city , a student went 1 / 5 of the way by foot , 2 / 3 of the way by bus , and the remaining 10 kilometers by car . what is the distance , in kilometers , from the dormitory to the city ?
62

Problem: two cubes have their volumes are in the ratio 1 : 27 . find the ratio of their surface area ?

1 : 9', 'd ) 2 : 7', 'e ) 3 : 11'