A runs ⁷/₄ times as fast as B. If A gives B a start of 300 m, how far must the winning post be if both A and B have to end the race at same time?

Explanation:-

.	A	B	Reason (ST=D)
Speed	7	4	Given
Time	4	7	Since, Speed ∝ 1/time
Distance	4	7	Distance ∝ time

Now,
7x - 4x = 300 (A runs 7x m and B runs 4x)
x = 100
7x = 7 * 100 = 700 m
Winning post is 700 m away, As A runs 700 m to complete the race.