[StudentXIIStd]

I am a student of XII std and unable to get the answer for this question:

A forms a CCP. A atoms are in the corners, B atoms are at the alternate face what is the formula of the compound?

My understanding is that

A atoms : 8 x 1/8  = 1
B atoms = 3 x 1/2 = 3/2

Formula of compound = A₂B₃

OR

A atoms : 8 x 1/8  = 1
B atoms = 6 x 1/2 = 3

Formula of compound = AB₃

Is my understanding correct or which is the correct formula for the compund?