Question

In a $100m$ race, $A$ can beat $B$ by $25m$ and $B$ can beat $C$ by $4m$. In the same race, $A$ can beat $C$ by :

• A. $29m$
• B. $21m$
• C. $26m$
• D. $28m$

Answer 1

The correct option is D $28m$

So, $A:B=100:75$

$B:C=100:96$

Therefore,

$A:C=(\frac{A}{B}\times \frac{B}{C})=(\frac{100}{75}\times \frac{100}{96})=\frac{100}{72}=100:72$

Thus, $A$ beats $C$ by $(100-72)=28$ $m$.