A crystal is made of particles A and B. A forms fcc packing and B occupies all the octahedral voids. If all the particles along the plane as shown in figure are removed, then, the formula of the crystal would be:

Effective no. of A particles are removed=4×18+2×12=32Effective no. of A particles present in a unit cell=4-32=52Effective no. of B particles are removed=2×14+1=32Effective no. of B particles present in a unit cell=4-32=52A : B52 : 521 : 1