Record size = 200B
Let there are x records to be stored in each block.
then Each block holds data = 200xB and nondata overhead = 250B.
The number of blocks that can fit on a track = 40,000 / (200x + 250) = 32
200x+250 =1250 => x = 5
so, There are five 200B records per block , that means Blocking factor is 5