Answer in Statistics and Probability for Marine Smit #88207

The binomial probability formula is the result of getting exactly k successes in n number of trials.

“P(k success in n trials)=begin{pmatrix}n n \n knend{pmatrix}p^k(1-p)^{n-k}”

We have that

“n=10, p=0.3”

1.1 At least 2 will have a medical aid 

“P(Xgeq 2)=1-(P(X=0)+P(X=1))=”

“=1-begin{pmatrix}n 10 \n 0nend{pmatrix}0.3^0(1-0.3)^{10-0}-begin{pmatrix}n 10 \n 1nend{pmatrix}0.3^1(1-0.3)^{10-1}approx 0.850692”

1.2. More than 9 will have a medical aid

“P(X> 9)=P(X=10)=begin{pmatrix}n 10 \n 10nend{pmatrix}0.3^{10}(1-0.3)^{10-10}approx 0.000006”