1.  In a 100 m race, A can give B 10 m and C 28 m. In the same race B can give C:
A. 18 m
B. 20 m
C. 27 m
D. 9 m

Answer: Option B

Explanation:

A : B = 100 : 90.

A : C = 100 : 72.

B : C = B x A = 90 x 100 = 90 .
A C 100 72 72

When B runs 90 m, C runs 72 m.

When B runs 100 m, C runs 72 x 100 m = 80 m.
90

B can give C 20 m.