Question

The area of a rectangular field is 3584 m and its length is 64 m. A boy runs around the
field at the rate of 6 km/h. How long will he take to go 5 times around it?​

Answer 1

$\red{\bigstar}$ Time taken $\large\leadsto\boxed{\rm\pink{12 \: minutes}}$

• Given:-

• Area of rectangular field = 3584 m

• Length of rectangular field = 64 m

• Speed of the boy = 6 km/hr.

• To Find:-

• Time taken to cover 5 times around it.

• Solution:-

We know,

• Area of a rectangle:-

$\large\underline{\boxed{\bf\green{Area \: of \: rectangle = Length \times Breadth}}}$

→ $\sf 3584 = 64 \times Breadth$

→ $\sf Breadth = \dfrac{3584}{64}$

★ $\bf Breadth = 56 \: m$

Now,

• Perimeter:-

$\pink{\bigstar}$ $\large\underline{\boxed{\bf\green{Perimeter = 2(l + b)}}}$

→ $\sf Perimeter = 2(64 + 56)$

→ $\sf Perimeter = 2 \times 120$

★ $\bf Perimeter = 240 \: m$

• The boy takes 5 rounds:-

→ $\sf 240 \times 5$

→ $\sf 1200 m$

→ $\sf \dfrac{1200}{1000} km$

★ $\bf\red{1.2 \: km}$

• Time taken to cover 5 rounds:-

We know,

$\pink{\bigstar}$ $\large\underline{\boxed{\bf\green{Time = \dfrac{Distance}{Speed}}}}$

→ $\sf Time = \dfrac{1.2}{6}$

→ $\sf Time = 0.2 hour$

→ $\sf Time = 0.2 \times 60 min.$

★ $\bf\red{Time = 12 \: min.}$

Therefore, time taken to cover 5 rounds is 12 minutes.