Question

$A$ runs $100$ meters in $11$ seconds and $B$ runs $100$ meters in $12$ seconds. The start which must be given to $B$ to make the race to be completed in $11$ seconds with a draw will be

• A. $8$ m
• B. $8\frac{1}{4}$ m
• C. $8\frac{1}{3}$ m
• D. $8\frac{1}{2}$ m

Answer 1

Answer: (C)

$8\frac{1}{3}$ m

Speed of A $=\frac{100}{11}m/s$, Speed of B $=\frac{100}{12}m/s$
Required distance (given to B) $=$ (Distance covered by A in 11 seconds) - (Distance covered by B in 11 seconds)
$(\frac{100}{11}\times 11)m-(\frac{100}{12}\times 11)m$
$=100m-91\frac{2}{3}m$
$=8\frac{1}{3}$.