The length and breadth of a rectangular park are in the ratio 2 : 1. A cyclist riding along the boundary of the park at 18 km/h completes one round in 10 minutes. What is the area of the park?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → 5,00,000 m2
One round of the boundary is the perimeter, and the distance covered is speed × time. Change the speed to metres per second first.
\(\displaystyle 18\text{ km/h}=18\times\frac{5}{18}=5\) m/s
10 minutes \(=600\) s
Perimeter \(=5\times600=3000\) m
Sides \(2k\) and \(k\): \(2(2k+k)=6k=3000\), so \(k=500\)
Length \(=1000\) m, breadth \(=500\) m
Area \(=1000\times500=5,00,000\) m2
