If p varies jointly as q and r, and p = 150 when q = 18 and r = 5, find q when p = 345 and r = 9. q=

q = 23

Step-by-step explanation:

Given p varies jointly as q and r then the equation relating them is

p = kqr ← k is the constant of variation

To find k use the condition p = 150 when q = 18 and r = 5, then

150 = k × 18 × 5 = 90k ( divide both sides by 90 )

= k , that is

k =

p = qr ← equation of variation

When p = 345 and r = 9 , then

345 = q × 9 = 15q ( divide both sides by 15 )

23 = q

my guess would be b and d, but i didn’t actually get out the pen and paper. lol