X and Y are continuous values, both measured to 2 significant figures. X=230 and Y=400. work out the greatest possible value of X/Y^2.
(this is on an upper and lower bounds sheet)

"Two significant figures" means that a digit after the second one could actually be anything ... it wasn't measured. 'X' could be anything from 230 to 239. 'Y' could be anything from 400 to 409.
The greatest possible value of that fraction is. (239)/(409 squared) .