Question

A park is 1500 metres long and 750 metres
wide. A cyclist has to take four rounds of
this park. How much time he will take at the
speed of 4.5 km/h ?
(A) 40 hours (B) 20 hours
(C) 10 hours (D) 4 hours​

Answer 1

The time is "D) 4 hours".

Step-by-step explanation:

Given,

The length of park(l) = 1500 metres, the breadth of park(b) = 750 metres and

speed = 4.5 $\dfrac{km}{h}$

To find, the time(t) = ?

We know that,

The perimeter of rectangle = 2(l + b)

∴ The perimeter of rectangular park =2(1500 + 750) m

= 4500 m

The total distance of four round of the park = 4 × 4500 m

= 18000 m = 18 km

∴ Speed = $\dfrac{Distance}{Time(t)}$

⇒ Time(t)$=\dfrac{Distance}{Speed}$

$=\dfrac{18}{4.5}=4hours$

Hence, the time is "D) 4 hours".

Answer 2

Answer:

A park is 1500 metres long and 750 metres  wide. A cyclist has to take four rounds of  this park.  he will take 4 hours to complete the four

Step-by-step explanation:

To answer this question, we must first calculate the perimeter of the park.

The park is in form of a rectangle.

Perimeter of the rectangle = (Length +  Width)2

This equals to: (1500 + 750)2

= 2250 × 2 = 4500 m

The perimeter of the park is 4500 meters.

The Cyclist takes four rounds.

Four rounds is equivalent to; 4500 × 4 = 18000 meters

So, the cyclist covers a distance of 18000 meters.

Since the speed is given in km/h, we convert this distance to kilometers.

1km = 1000m

so we have: 18000/1000 = 18 km

Given speed and distance, the formula for getting time is:

Time = Distance/Speed

= 18/4.5 = 4 hours.