2001 paper help needed (1 Viewer)

[**blu_rose**]

can someone please help me with q 28 the one with the pizzas and the diameter etc, 2001 hsc paper
i kinda forgot how to do that stuff

 

[100percent]

can someone please help me with q 28 the one with the pizzas and the diameter etc, 2001 hsc paper
i kinda forgot how to do that stuff

28ai)
n=kd²
sub in mini size
8=k20²
8=400k
8/400=k
0.02=k

aii)
n=kd²
n=0.02x52²
n=54.08
so you need 55

aiii)
square area 25²=>625
circle area = pi x radius²
625=pi x radius²
radius approx 14.10cm
diameter=28.20
n=kd²
n=0.02x28.20²
n=15.90
so he needs 16