Professor Layton offers DS owners a break from their daily Brain Training/Maths Training/Whatever with some seriously interesting problems and riddles. There's a lot more satisfaction in solving problems to progress in the story than in hearing the DA-DING of Brain Training for adding 3+5.
Now….A glass jar holds a single germ. After one minute, the germ splits into two germs. One minute after that, the two germs each split again, forming a total of four germs. Continuing at this rate, a single germ can multiply to fill the whole jar in exactly one hour. Knowing this, how long in minutes would it take to fill the jar if you had started with two germs?