In a kilometre race, A can give B a start of 100 m or 15 seconds. How long does A take to complete the race?  Choose the correct option:
A) 150 seconds
B) 165 seconds
C) 135 seconds
D) 66.67 seconds
E) 180 seconds
Explanatory Answer   In a 1000 metre race A gives B a start of 100 m or 15 seconds.   This essentially means that B takes 15 seconds to run 100 m.   Therefore, B will take 150 seconds to run the stretch of 1000 metres. (1000 m = 10 times 100 m and therefore the time taken will also be 10 times 15 seconds = 150 seconds).   As A gives B a start of 15 seconds, A obviously takes 15 seconds less than B to complete the race.   Hence, A will take 135 seconds to run the 1000 m.   Answer 135 seconds
<result>C</result>
In a kilometre race, A can give B a start of 100 m or 15 seconds. How long does A take to complete the race?