Question

Three variables p, q and r are such that p varies directly as q and inversely as the square of r.

1. When p=9, q12 and r = 2.
   Find p when q= 15 and r =5 
2. Express q in terms of p and r.

Answer 1

1. P=kQ/r²
   9= 12k/2²
   k=9/3 =3
   P= ³⁽¹⁵⁾/₂₅
   P=1.8
    
2. P=KQ/r²
   (pr²)/3=q