Probability and statistics with Poisson Distribution!!

2) Two administrative assistants are available to take minutes at a departmental meeting. The minutes include much technical information and some formulas. Pam has an average of 1.7 errors when the minutes are printed out, and Marnie has an average of 3.9 errors when the minutes are printed out. The number of errors per printout can be approximated by a Poisson distribution. If the minutes are equally likely to be taken by either administrative assistant, find the probability that there will be no errors. (Hint: Find probability that Pam will do them AND she has no errors, OR , that Marnie will do them AND she has no errors. )