Question 363430
A){{{0.75*160=120}}}
B)We have to solve the equation {{{1-0.25^n - n*(0.75)*0.25^(n-1) - ((n(n-1))/2)*(0.75^2)*0.25^(n-2) = 0.995}}}.  The closest value of n that would work for this is n = 8:
{{{1-0.25^8 - 8*(0.75)*0.25^7 - ((8(7))/2)*(0.75^2)*0.25^6 = 0.99577}}}.