1.  In a 100 m race, A beats B by 10 m and C by 13 m. In a race of 180 m, B will beat C by:
A. 5.4 m
B. 4.5 m
C. 5 m
D. 6 m

Answer: Option D

Explanation:

A : B = 100 : 90.

A : C = 100 : 87.

B = B x A = 90 x 100 = 30 .
C A C 100 87 29

When B runs 30 m, C runs 29 m.

When B runs 180 m, 

C runs29x 180m= 174 m.
30


B beats C by (180 - 174) m = 6 m.