Question 757169
three squares have sides with lengths a,b and c. 
if b is 20%greater than a, c is 25%greater than b, 
so b=a+20%a=1.2a
& c=b+25%b=1.25b=1.25*1.2a=1.5a
so the sides of the 3 squares are a,1.2a & 1.5a
now it is clear that greatest square is of sides 1.5a & smallest is of a
so the areas are (1.5a)^2=2.25a^2 & a^2
the percent difference in the area of the largest square & the smallest square
=(2.25a^2-a^2)*100/a^2=(2.25-1)*100=125%