Most likely the 3 that earns credit will be a null or void credit. An example of a void credit is this - The California UC system gives graduation credit for Calc 2 with a 3 in AP Calc BC. But for UC-Berkeley L&S, you need a 5 in order to get subject credit (4 for Engineering). So with a 3 in BC, you get the credit but in order for you to continue on with further Math classes, you need to take Calc 2 since you didn’t get subject credit for it. Once you take Calc 2, the credit you got from AP gets voided.