fair <- rbinom(90000, 20, .5)
sum(fair == 14)
# [1] 3410

biased <- rbinom(10000, 20, .75)
sum(biased == 14)
# [1] 1706

$$\frac{\text{\# of biased w/14 Heads}}{\text{\# total w/14 Heads}}$$

$$\frac{1706}{1706+3410}=.333$$