Question

Rajneetha walks around the circular park in 15 minutes.If she walks at the rate of 5 km/hr, how much distance would she have to travel, at the minimum, to reach the centre of the park from any point on its perimeter?

• A. $100$ metre
• B. $200$ metre
• C. $250$ metre
• D. $300$ metre

Answer 1

Answer: (B)

$200$ metre

Rajneetha covers around park $2\pi r$ in 15 minutes at speed 5 km/hr
Distance covered$=S\times T$

$=5\times 15\times 60\times 1000\times \frac{1}{3600}m$
$=1250m$
$2\pi r=1250m$
$r=\frac{1250\times 7}{2\times 22}=198.86\approx 200m$ approx