To get the equivalent yearly increase of x% we use the compound formula given by: A=P(1+r/100)^t where: A=amount, P=principle, r=rate, t=time from the question: A=£95000, P=£80000, r=x%, t=5 years hence plugging the values we obtain: 95000=80000(1+x/100)^5 simplifying the above we obtain: 1.1875=(1+x/100)^5 1.03497=1+x/100 0.03497=x/100 thus x=3.497~3.5%