A can give B 100 meters start and C 200 meters start in a kilometer race. How much start can B give C in a kilometer race ?

Explanation:

A runs 1000 m while B runs 900 m and C runs 800 m.
The number of meters that C runs when B runs 1000 m,
= (1000 * 800)/900 = 8000/9 = 888.88 m.
B can give C = 1000 – 888.88 = 111.12 m.