Question

The cost of the circular carpet, $C, varies as the square of the radius,

r metres. If C = 200 when r= 2
Find the cost of the circular carpet when r= 3

Answer 1

$450

Explanation:

C = k
`r^(2)`

200 = k(
`2^(2)`) = 4k

k = 50

C = 50
`r^(2)` = 50(
`3^(2)`) = 50(9) = $450