Question

A sprinkler sprays water in a circular area up to 30 feet. A radius reduction screw lets people reduce the radius by up to 25%. What is the maximum area of lawn that can be watered if the radius reduction is at full capacity.

Answer 1

Answer: $1590.63\ ft^2$

Step-by-step explanation:

Given

The sprinkler can water the area up to $30\ ft$  i.e. $30\ ft$  is the radius

If the screw leads to a reduction of 25% in radius, then the new radius is

$r'=(1-0.25)r\\r'=0.75r\\r'=22.5\ ft$

So, the area corresponding to this radius

$\Rightarrow \pi (22.5)^2\\\Rightarrow 1590.63\ ft^2$

Thus, the maximum area that can be covered is $1590.63\ ft^2$