please i need help in solving these questions

#1
hi all, please can anyone help me :(

1. The internal auditing staff of an local manufacturing company performs a sample audit each quarter to estimate the proportion of accounts that are delinquent more than 90 days overdue. The historical records of the company show that over the past 8 years 13 % of accounts are delinquent. For this quarter, the auditing staff randomly selected 25 customer accounts. What is the probability the no more than 40 accounts will be classified as delinquent?


2. A PH.D graduate has applied for a job with two universities, A and B. the graduate feels that she has a 60% chance of receiving an offer from university A, and a 50% chance of receiving an offer from university B. if she receives an offer from university B, she believes that she has an 80% chance of receiving an offer from university A:
- What the probability that both universities will make her an offer?
- What the probability that at least one university will make her an offer?
 
#3
question no.1 i didn't know to start :(
for the second question i solve it like this

p(A and B) = p(A) * p(A/B)= .6 * .8 = .48
p(A or B) = p(A) + p(B) - p(A and B) = .6 + .5 - .48 = .62 .... but i got zero
 

noetsi

Fortran must die
#4
For this quarter, the auditing staff randomly selected 25 customer accounts. What is the probability the no more than 40 accounts will be classified as delinquent?
I would say the probability was zero because if you only surveyed 25 accounts you obviously can't find 40 accounts delinquent since 40 > 25 :p

Are you sure you provided all the information from the question?