In a race of 200 meters, B can gives a start of 10 meters to A, and C can gives a start of 20 meters to B. The starts that C can gives to A, in the same race is:

Answer: Option C

According to question,
When B runs 200 m meters, A runs 190 meters;
Hence, when B runs 180 meters,
A runs = $$\frac{190\times 180}{200}$$   = 171 meters;
When C runs 200m, B runs 180 meters.
Hence,
C will give a start to A by = 200 - 171
= 29 meters