q in bio, need help.

Question

blues vary inversely as purples cubed. when there are 250 blues, there are 2 purples. how many blues are present when there are 5 purples? 

Answer 1

b = number of blues

p = number of purples

 

b = c/p³,

 

where c is a constant.

 

250 = c/2³ = c/8 ⇒ c = 2000

 

b = 2000/p³

 

p = 5 ⇒ b = 2000/5³ = 16