A batch reactor produces 1×10⁵ kg of a product per year. The total batch time (in hours) of the reactor is k√P_B, where P_B is the product per batch in kg and k=1.0 h/√kg. The operating cost of the reactor is Rs. 400/h. The total annual fixed charges are Rs. 340×P_B and the annual raw material cost is Rs. 2×10⁶. The optimum size (in kg) of each batch (adjusted to the nearest integer) is