At peak periods, 15% of attempted log-ins to an email service fail. Log-ins attempts are independent and each has the same probability of failing. Ann logs in repeatedly until she succeeds.

Question

At peak periods, 15% of attempted log-ins to an email service fail. Log-ins attempts are independent and each has the same probability of failing. Ann logs in repeatedly until she succeeds. 
A. find the probability that Ann needs to log in at least four times before she succeeds. 
B. What is a standard deviation for number of log-ins needed to succeed 
Please HELP!!!Thank you so much!