(A) 12 m
(B) 16 m
(C) 24 m
(D) 48 m
Correct Option is: D
Let the length of the race track be ‘d’.
When Y finished the race, X and Z would have run (d−18) and (d−12) meters respectively.
When Z finishes the race, X would have run (d-8) meters.
The ratio of speeds of Z and X is:
(d-12)/(d-18) =d/(d-8)
(d-8)(d-12)=d(d-18)
d2
-12d-8d+96 = d2
-18d
d2
-20d+96= d2
-18d
20d-18d=96
d=96/2=48m
hence the length of the race track is 48m