If a bacterial cell divides once in every minute, it takes one hour to fill a cup. How much time will it take to fill half of the cup ?

If the life cycle of a bacteria is 1 minute, it means that the  bacterial cells divide every 60 seconds. So if it takes 60 minutes to fill a cup, it must take 59 minutes to fill half a cup as in 1 minute half cup full of bacteria will double to fill the cup completely.