What is the probability that Fatima gets fewer heads than tails if she flips 10 coins?
Probability of 0 heads = C(10, 0) / 2^10
Probabilty of 1 head = C(10,1) / 2^10
Probability of 2 heads = C(10,2) / 2^10
Probability of 3 heads = C(10,3) / 2^10
Probabilty of 4 heads = C(10, 4) / 2^10
So....the probabilty of getting fewer heads than tails =
[ C(10,0) + C(10,1) + C(10,2) + C(10,3) + C(10,4) ] / 2^10 = 193/512 ≈ .377 = about 37.7%