How badly will a fail grade hurt me?

I'm Asian Female and I have a degree in Business Administration from a good university in the UK. I have a first-class degree, which is equivalent to a GPA of 3.75. However, this is only because in the UK the final year counts for 70 % of my grade, my second year count for 30% of my grade and my first year does not count at all. I didn't really put in much effort in my first year-and-a-half, and my grades were mediocre, including one failure in a quant course. However, my grades rose steeply in the second half of my degree and I have a 740 GMAT.

Does this totally destroy my chances of getting intoa good B-School or this there anything I can do to improve my chances? I am planning on applying to B-School only in 2015, so I still have some time, if I can do something to imrpove my chances.