so, if the original prize is x, then 29.99 is 30%x (it's 70% savings, so 100%-70%=30%).
so, 29.99=30%x
29.99=0.3x
then x=29.99/0.3
and x=99.966666
well, it's unlikely that this was the original prize, and probably the actual prize was 100, but they just took off one cent from the prize after the reduction - it's a common marketing strategy