So before the move, that is, after the fourth move, the ratio of A to B is 3: 1.
Similarly, after the third move, a is 1.5:2.5 (this ratio is that the upper large number is half; the decimal number is half of the large number, and the lower one is the same calculation ratio. As for why this proportion is calculated, please understand it yourself.)
The second move is followed by 2.75: 1.25.
After the 1 move, it is 1.375:2.625.
Before the 1 th movement, the ratio of A to B was 2.6875: 1.5438+025.
A is between 560 and 640 at first, so the ampere ratio is calculated as b, and b can only be an integer.
It can be concluded that there are 602 A and 294 B.
2。 It's simple. Deal cards backwards from the last card. The order is C → B → D → A, and the order is reversed.