The race ends at half past 6 in the evening. What is this time in 12 hour clock time?

6:30 pm

but i think you mean 24 hour clock because you basically have told the answer

18:30

or half past 18

i guess u meant the 24 hour clock ... if it is 12 hour clock ... the answer is already thr in the question = half past 6

if it is the 24 hour clock ... the answer will be 18 : 30

reason : now if u c a 12 hour clock ... after 12 noon ... it becomes 1 again the 2 then 3 ... so on ...

but in the case of a 24 hour clock ... after 12 noon it goes on like ... 13, 14, 15, ect ...

so 12 : 30 + 6 = 18:30