According to records from the last 50 years, there is a 2/3 chance of june temperatures being above 80 f. azul needs to find the probability that it will be above 80' f for 20 or more days this june. there are 30 days in june. use the simulation data to find the probability

Here we shall use the binomial distribution formula to evaluate the probability:
let the probability that the temp will be above 80 be P(F)=2/3; 
Probability that the temp will be below 80 be P(F')=1/3
thus, 
The probability that the temp will be above 80 for 20 days for the month of June will be:
P(F)=n!/((n-x)!x!)p^xq^(n-x)
p=2/3 and q=1/3, n=30, x=20
plugging the values in the equation we obtain:
P(F)=30!/(10!*20!)*(2/3)^20*(1/3)^(30-20)
P(F)=0.153