Step-by-step explanation:
the other parts base on A and B ...
but ok.
A.
the hourly rate is
15 monetary units / hour
B.
we get A actually from here :
small triangle : 15/1 or 15:1
medium triangle : 30/2 or 30:2 = 15:1
large triangle : 60/4 or 60:4 = 15:1
so, we see it all boils down to 15 monetary units to (or per) 1 hour.
