for 60secs to fill a bag, u need 2^60 bean
if u being with 2 beans, u end up 2x faster then the original timing because 2^60/2^59 = 2 !! which is 30 secs
maybe i explain it more simple for you.
1st, u need 59x of expansion to fill the room if got 1 bean.
So let it be 2^0 to 2^59
if u start with 2 bean, it wil be 2^1 to 2^59, which effectively is 58x of expension 2^59/2^58 = 2, and 60/2 = 30secs


i don't understand at all
but its ok
i seriously think that 59 secs is the answer
i don't know how to prove your math approach wrong
initially i thought of using your methos of 2^60
but somehow it didnt get the right answe
maybe i'm really stupid like you said
hahahahax !!!