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?

Question

my question seems like a simple one but it is confusing so try to explain the answer in a way that a dumb person could understand

Answer 1

Varies inversely looks like this: B (blue) P^3 = k.  K is a constant; it is always the same because when B gets bigger, P gets smaller, and vice versa.  a simpler way to express it is xy = k, with k a constant number (always the same)

 

So, B x P^3 = k

And, 250 x 2^3 = k

Solve: 250 x 8 = 2000.  k = 2000

So, B x 5^3 = 2000

Simplify: B x 125 = 2000

              B = 16

Answer 2

y = number of blues

x = number of purples

 

 

y = k/x³

 

250 = k/2³ = k/8

 

k = 8(250) = 2000

 

y = 2000/x³

 

When x = 5,

 

y = 2000/5³ = 16

 

Do not call yourself dumb.  That is self-defeating.  You can learn, and math tutors are available to help.