This should be the distribution law of Bernoulli distribution (binomial distribution)

That is, an experiment is repeated n times, and there are only two results each time. The probability of the event is given by you above as p=0.2.

So P5 (4) = 5 * (0.2) 4 * 0.8 * is the power of the sign?

P3( 1)=3*0.2*0.8*0.8

P3(2)=3*0.2*0.2*0.8

P7(4)=35*(0.2)^4*(0.8)^3

P6(2)= 15*(0.2)^2*(0.8)^4

I am too lazy to count. Help yourself.