Question

Mr Jenkins has a grass lawn that is 24m wide and 30m long. Mr Jenkins cuts the grass at a rate of 9m2 per minute. How long will it take mr Jenkins to cut all the grass

Answer 1

Answer:

Length of the grass lawn = 30 m

Width of the grass lawn = 24 m

Hence the Area of the grass lawn is given as:

Area = Length × Width

⇒ Area of the grass lawn = 30 m × 24 m

⇒ Area of the grass lawn = 720 m²

Hence the area of Mr. Jenkin's grass lawn is 720 m².

Now it is given that, the rate at which the grass is cut, is 9 m² per minute.

Hence to cut all the grass of the lawn, the time taken would be:

⇒ Total Time = Total Area / Rate per m²

⇒ Total Time = 720 m² / 9 m²/min

⇒ Total Time = 80 minutes

Hence the total time taken by Mr. Jenkins to cut all the grass is 80 minutes (or) 1 hour 20 minutes.

Answer 2

Gɪᴠᴇɴ :

• Wide of a grass lawn is 24 m.

$\longmapsto\:\bf{Breadth\:(b)\:=\:24\:m}$

• Length of the grass lawn is 30 m.

$\longmapsto\:\bf{Length\:(l)\:=\:30\:m}$

• Mr. Jenkins cuts the grass at a rate of 9 m²/min.

➻ That means Mr. Jenkins cuts the area of his grass lawn at the rate of 9 m²/min.

$\longmapsto\:\bf{Rate\:=\:9\:m^2/min}$

Tᴏ Fɪɴᴅ :

• Time taken to cut all the grass.

Cᴀʟᴄᴜʟᴀᴛɪᴏɴ :

➣ From the given data, the shape of the grass lawn is rectangular.

Tʜᴜs,

↝ Area of the rectangle is,

$\red\bigstar\:\:{\underline{\orange{\boxed{\bf{\green{Area\:=\:Length\times{Breadth}}}}}}}$

➛ $\bf{Area\:=\:30\times{24}}$

➛ $\bf{Area\:=\:720\:m^2}$

Nᴏᴡ,

Wᴇ ᴋɴᴏᴡ ᴛʜᴀᴛ,

$\pink\bigstar\:\:{\underline{\green{\boxed{\bf{\blue{Time\:=\:\dfrac{Area}{Rate}}}}}}}$

➙ $\bf{Time\:=\:\dfrac{720\:m^2}{9\:m^2/min}}$

➙ $\bf\purple{Time\:=\:80\:min}$

$\Large\bf{Therefore,}$

Time taken by Mr. Jenkins to cut all the grass is 80 minutes.