A’s speed is 21/19 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?	Choose the correct choice from the following answers: A) 2/21 B) 2/19 C) 1/11 D) 1/7 E) 1/5
Let D be the full distance.   Let x be the fraction of the distance that B runs.   Let v be the speed at which B runs.   The time should be the same for both runners.   Time = D / (21v/19) = xD/v   (19/21)*D/v = x*D/v   x = 19/21   B should have a head start of 2/21 of the full distance.   The answer is 2/21.
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A’s speed is 21/19 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?