My data comes in like this:

Type ID Group
B BOX017 VR
A BOX017 S1
B BOX017 S1
A BOX234 S1
B BOX017 S1
B BOX017 GK




I am trying to find a formula for cell B2 below that will count the number
of occurances of Type=A, ID=BOX017, and Group=S1.

ID Type A
BOX017 1

Thank you in advance.