A3. From each bubble, two new ones emerge every second. How many new bubbles will have formed in 10 seconds, if the process started with one bubble?
(A) 256
(B) 512
(C) 660
(D) 1024
(E) 2048
A3. In the 1st second, there is 1 bubble in the process - then 2 new ones emerge from this bubble, in the 2nd second these 2 bubbles are in the process, from which 4 new ones emerge. Thus, in the 3rd second, there are 4 bubbles in the process, in the 4th second there are 8 bubbles, in the 5th second 16 bubbles, in the 6th second 32 bubbles, in the 7th second 64 bubbles, in the 8th second 128 bubbles, in the 9th second 256 bubbles, and in the 10th second 512 bubbles, from which 1024 new ones then emerge.