Question

In a $500$ m race ,the ratio of the speed of two contestants A and B is $3$ : $4$. $A$ has a start of $140$ m .Then A beats B by

• A. $60$ m
• B. $40$ m
• C. $20$ m
• D. $10$ m

Answer 1

Answer: (C)

$20$ m

To reach the winning post $A$ will have to cover a distance of $(500-140)m=360m$.

As the ratio of speeds is $3:4$

$A$ covers $3m$, $B$ covers $4m$.

While $A$ covers $360m$, $B$ covers $\frac{4}{3}\times 360=480m$.

Thus, when $A$ reaches the winning post, $B$ covers $480m$ and therefore remains $(500-480)m$ behind.

$\therefore A$ wins by $20m$.