Question 1086143
Use the area of a circle,
{{{A=pi(D/2)^2=(pi/4)D^2=(pi/4)(23)^2}}}
So the cost would be that cost per area multiplied by the area,
{{{C=0.05A}}}
{{{C=(1/20)(pi/4)(529)}}}
{{{C=(529/80)pi}}}
I'm assuming there are 100 cents in a rand.
C is in units of rands.
Work out the final answer with a calculator.