The cost of a circular table is directly proportional to the square of the radius. A circular table with a radius of 50cm costs £60. What is the cost of a circular table with a radius of 75cm? Show all your working

£135 is the correct answer.

Step-by-step explanation:

Let C be the cost of table.

And let R be the radius of table.

Cost of table is directly proportional to square of radius.

As per question statement:

or

where is the constant to remove the .

It is given that

£60 and

when

Putting the values of and in equation (1):

Putting the values of and in equation (1):

Dividing equation (2) by (3):

So, £135 is the correct answer.