The speeds of A and B are in the ratio 3:4. B gives A a start of 30 m. How far should the winning post be so that the race ends in a dead heat?
A
100 m
B
200 m
C
150 m
D
120 m
Correct Option - D
Explaination
Let A's speed be 3x m/s and
B's speed be 4x m/s
Let the distance of the winning post be l m.
Time taken by A to finish the race
= (l-30)/3x
Time taken by B to finish the race
= l/4x
For the race to end in a dead heat,
(l-30)/3x = l/4x
Solving,
l = 120 m