## Thinking Mathematically (6th Edition)

$\frac{1}{4}$
P(E) = $\frac{no.\ of\ outcomes\ in\ favor}{Total\ no.\ of\ outcomes}$ Given that H is heads and T is tails, the set of equally likely outcomes is: S = {HH, HT, TH, TT}. E: two heads Favorable outcomes= {HH} P(E) = $\frac{1}{4}$