We know that volume of cuboid = length × breadth × height
Volume of the block = 500 × 70 × 32 = 1120000 cm3
Volume of each plank = 2 × 25 × 8= 400 cm3
Therefore, total number of planks that can be made
= Volume of the block/ volume of the each plank
= 1120000/400
= 2800 planks