The correct rate of B test: 8/ 10* 100%=80%.

Choose three questions in each exam, and the probability of passing the A exam is 3*60%= 18%.

Probability of passing the B test: 3*80%=24%

Choose three questions from the exam. The probability of correctly passing two answers: 2/3* 100%=66.67%.

Therefore, the probability that at least one of Party A and Party B is qualified is 0.