1, the speed of A is 50% slower than that of B, that is, "1", which is 50% slower than "1", that is, 1-50%, and the speed of A is equivalent to 50% of that of B.

The speed of B is 50% faster than that of A, that is, the speed of A is regarded as "1", which is 50% faster than that of "1", that is, 1+50%, and the speed of B is equivalent to 150% of the speed of A. ..

2. The speed of Party A is twice that of Party B, that is, the speed of Party B is regarded as "1", which is twice as fast as "1", that is, 1+2, and the speed of Party A is three times that of Party B. ..

B is twice slower than A, which is inaccurate. In this question, the speed of A is regarded as the unit "1", which is twice slower than "1", but only 1/2 (or 50%), that is, 1- 1/2.

You can draw a line graph, which is helpful for understanding.