Question

X, Y and Z are three contestants in a race of 1000 m. Assume that all run with different uniform speeds. X gives Y a start of 40 m and X gives Z a start of 64 m. If Y and Z were to compete in a race of 1000 m, how many metres start will Y give to Z?

(a) 20

(b) 25

(c) 30

(d) 35

Answer 1

Correct option is (b) 25

X gives Y a start of 40m, so when Y complete 960m X will complete 1000m 

Speed of X : Speed of Y = 1000 : 960 

⇒ 25 : 24 

Similarly X give Z a start of 64 m, so when Z complete 936m X will complete 1000m 

speed of X : speed of Z = 1000 : 936 

⇒ 125 : 117

So, 

Speed of Y : speed of Z = 40 : 39 

so, when Y complete 1000m Z will complete 975m.