Doubt from Solid State

Please tell me the answer.

approx 10

but answer is given 8

See my answer is correct if they r including 1st nd lst

No, it'll still be 8.

logic????
1 unit cell 3 lyer height 4r(..) divide by given height u will get 10 layer
i think if wrong correct me
@Abhishek_2020_5

Two consecutive U.C. will have a layer in common.

Correct