Subject: mathqa
Question: a ’ s speed is 25 / 18 times that of b . if a and b run a race , what part of the length of the race should a give b as a head start , so that the race ends in a dead heat ?
Option: 
A: 7 / 25
B: 7 / 18
C: 1 / 18
D: 1 / 25
Answer: A