Question 464685
{{{P(X = 0,1,2) = 20C0*0.60^20*0.40^0 + 20C1*0.60^19*0.40^1 + 20C2*0.60^18*0.40^2 = 0.0036}}}

{{{P(X = 4) = 20C4*0.60^16*0.40^4 = 0.0350 }}}

{{{1  - P(X = 0,1,2, 3) = 1 - 20C0*0.60^20*0.40^0 - 20C1*0.60^19*0.40^1 - 20C2*0.60^18*0.40^2 - 20C3*0.60^17*0.40^3 = 0.9840}}}