Question

How to do this question plz answer my question ​

Answer 1

$121.82

Explanation:

Okay, this is kind of complex, so let's go step by step.

First, we want to find the area of the rectangular lawn - we can do this by multiplying the length and width. The length is 100 and the width is 45 so
`45\cdot100=4500` m² is the area of the rectangle.

However, there are 3 ponds in which the grass seeds will not be going - so we need to find the area of all 3 of these circles and subtract it from 4500 (our rectangle area).

The area of a circle is represented by the formula
`\pi r^2`

The diameters are given here, which is double the radius, so to find the radius of each circle let's divide the diameters by 2.

First circle's radius:
`20/2=10`

Second circle's radius:
`10/2=5`

Third circle's radius:
`5/2=2.5`

Now let's find the area of each circle.

First Circle:
`\pi \cdot10^2 = \pi\cdot100=3.14\cdot100=314`

Second Circle:
`\pi\cdot5^2 = \pi \cdot25 = 3.14\cdot25=78.5`

Third Circle:
`\pi \cdot 2.5^2 = \pi \cdot6.25 = 3.14\cdot6.25=19.625`

Adding all of these values gets us 412.125.

Now we can subtract from this from 4500 to get us 4087.875

If the grass seeds that cost £1.49 cover 50m² each, then we need
`4087.875/50=81.7575` bags.

Each bag costs £1.49, so the total cost is
`81.7575\cdot1.49\approx121.82`

Hope this helped!!