How to write the steps of the big math probability problem in the new curriculum standard college entrance examination? Is it complicated to write: let ... become event A ... or directly list expressions and permissions? ... Let's write it ... as event a. Then write p(a)= 1 ...

C stands for the selected project.

If there is a probability, what is the reverse? What score?

Distribution list must be listed.

The second question to copy is ... x = ...

All p's add up to 1.

Ps, we are also prospective candidates ~