First, we can break down his pay into how much he gets each month. There are 12 months in a year so lets break his salary down into 12 payments :
71,000 / 12 = 5916.67
Now, if he receives a paycheck twice a month, we need to breakdown his monthly payment into 2. Thus, his bi-monthly paycheck is :
5916.67 / 2 = 2958.33