The winning relay team in a high school sports competition clocked 48 minutes for a distance of 13.2 km. Its runners A, B, C and D maintained speeds of 18 kmph, 19 kmph, 20 kmph, and 21 kmph respectively. What is the ratio of the time taken by B to than taken by D?	Choose the correct choice from the following options:
A) 5:16 B) 5:17 C) 9:8 D) 8:9 E) None of these
Explanation :   Since it is a relay race, all the runners ran the same distance.   Hence for a same distance, (ratio of times) = 1/(ratio of speeds).   Hence ratio of times taken by B t&amp; D = 21 : 19   Answer : None of these
<result>E</result>
The winning relay team in a high school sports competition clocked 48 minutes for a distance of 13.2 km. Its runners A, B, C and D maintained speeds of 18 kmph, 19 kmph, 20 kmph, and 21 kmph respectively. What is the ratio of the time taken by B to than taken by D?