Question

20 POINTS FOR ANSWER!!!

Answer 1

P varies directly with Q and inversely with R, on the contrary, P varies inversely with R, this means P and R are indirectly proportional. In simple terms it means whatever you do to P, you do the opposite to R. Or P=K*Q/R

18=k*5/2 
18=5k/2 
5k=36 
k=36/5 

P=K*Q/R 
p=(36/5)(20/10) 
p=72/5