4
8
pA=0.6 pB=0.7 pA0=0.4^3 pA1=0.4^2 * 0.6 * choose(3,1) pA2=0.4 * 0.6^2 * choose(3,2) pA3=0.6^3 pB0=0.3^3 pB1=0.3^2 * 0.7 *choose(3,1) pB2=0.3 * 0.7^2 *choose(3,2) pB3=0.7^3 ans1= pA0*pB0+pA1*pB1+pA2*pB2+pA3*pB3 ans1 # [1] 0.32076 ans2= (1-pA0)*pB0+(1-pA0-pA1)*pB1+pA3*pB2 ans2 # [1] 0.243
15
ans = 0 p = 0.0015 k = 0 while(k <= 10){ ans = ans + choose(5000, k) * p^k * (1 - p)^(5000 -k) k = k + 1 } ans [1] 0.8623991