Question

Two variables x and y are such that y varies directly as xⁿ where n is a constant. Given that y = 320 when r=16 and y =2560 when x = 64, find the value of n

Answer 1

y = cxⁿ
c = 320 = 256
      16ⁿ 64ⁿ
2  ⁴ⁿ = 32  
2⁶ⁿ     256
2⁻²ⁿ = 2⁻³
n = 1.5