Question 1151915
given probability that a student has:
 a Visa card (event V) is {{{.65}}}
a MasterCard (event M) is {{{.20}}}
a student has both cards is {{{.13}}}

(a) Find the probability that a student has either a Visa card or a MasterCard

The key word here is {{{OR}}}.

{{{P}}}({{{V}}} or {{{M}}}) ={{{ P(V)+P(M)}}}-{{{P}}}({{{V }}}and{{{ M}}})

{{{P}}}({{{V}}} or {{{M}}}) = {{{0.65 + 0.20 - 0.13 = 0.72}}}